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Title: Effects of Investigative Laboratory Integration on Student Content Knowledge and Science Process Skill Achievement across Learning Styles
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Copyright Date: 2008

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Permanent Link: http://ufdc.ufl.edu/UFE0003880/00001

Material Information

Title: Effects of Investigative Laboratory Integration on Student Content Knowledge and Science Process Skill Achievement across Learning Styles
Physical Description: Mixed Material
Copyright Date: 2008

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Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0003880:00001


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EFFECTS OF INVESTIGATIVE LABORA TORY INTEGRATION ON STUDENT CONTENT KNOWLEDGE AND SCIENC E PROCESS SKILL ACHIEVEMENT ACROSS LEARNING STYLES By BRIAN EUGENE MYERS A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2004

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Copyright 2004 by Brian Eugene Myers

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This document is dedicated to my wife Margaret and my son Timothy.

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ACKNOWLEDGMENTS I have often told others that throughout my life I have been a victim of good luck. I have been fortunate to have a number of excellent role models and friends that have helped shape and guide my life, both professionally and personally. I wish extend to my deep appreciation to my advisor, Dr. James Dyer, for his friendship, council, and encouragement throughout the completion of this document and the entire graduate program. I feel fortunate to have been able to spend this time under his supervision and guidance. He has shown me that there is a place in higher education for a professional who is deeply passionate about agricultural education. I am also grateful to the other members of the graduate committee, Dr. Ed Osborne, Dr. Shannon Washburn, Dr. Linda Jones, and Dr. Rick Rudd, for their assistance in this project. I have gained something from each of them that will make me a better faculty member. I also wish to extend my appreciation to Dan Pentony and the Center for Agricultural and Environmental Research and Training. Without their financial support, this project would not have been possible. I also wish to thank the following individuals: I thank my wife Margaret and son Timothy, for their love, support, and sacrifice. Without their encouragement I would not have been able to complete this program. They have taught me that no matter what educational degree I earn or position I hold, my most important titles will always be husband and father. iv

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I thank my parents, Eugene and Cheri Myers, for their love and support of all of us throughout the years. They have supported me in every endeavor I have undertaken. They have provided an example for all. I have only tried to live my life up to that standard. To my sister Emily, I do not think she knows how important she is to me. Although we do not get to spend a great deal of time together, she is always in my heart. I thank my grandparents, Lewis Dell and Harold and Mary Ann Myers, for being there for a boy to look up to, to play with, and to learn from. I know how lucky I am to have each of them in my life. I thank Charles Ferguson, my high school agriculture teacher. He planted the first seed of my becoming an agriculture teacher. I thank him for showing me how important a role that is. To Ben Spohr and Lucinda Kunz, without their support of a young agriculture teacher I do not think I could have made it. They showed me what it truly meant to be a teacher and part of the school community. Their dedication to the students, the school, and the community did not go unnoticed. To the entire group in 310 Rolfs Hall, through our time together we have grown to know each other quite well. We have been there for each other in the times of celebration and the times of disappointment. I know that I have become a better teacher, a better researcher, and a better person because of our time together. v

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TABLE OF CONTENTS Page ACKNOWLEDGMENTS.................................................................................................iv LIST OF TABLES...............................................................................................................x LIST OF FIGURES..........................................................................................................xii ABSTRACT.....................................................................................................................xiii CHAPTER 1 INTRODUCTION........................................................................................................1 Statement of the Problem..............................................................................................3 Purpose of the Study.....................................................................................................8 Statement of Objectives................................................................................................8 Statement of Hypotheses..............................................................................................8 Definition of Terms......................................................................................................9 Limitations of the Study.............................................................................................10 Assumptions of the Study...........................................................................................10 Chapter Summary.......................................................................................................10 2 REVIEW OF THE LITERATURE............................................................................13 Theoretical Model of the Teaching and Learning Process.........................................13 Product Variables........................................................................................................17 Student Content Knowledge Achievement.........................................................17 Science Process Skill...........................................................................................20 Process Variables........................................................................................................22 Subject Matter Approach.....................................................................................22 Experiential Learning..........................................................................................26 Inquiry-based Instruction.....................................................................................30 Laboratory Instruction.........................................................................................33 Context Variables.......................................................................................................34 Learning Style.....................................................................................................35 Learning Styles Instrumentation..................................................................35 Group Embedded Figures Test (GEFT)..................................................36 Myers-Briggs Type Indicator..................................................................37 Learning Styles Inventory (LSI).............................................................37 Research on Learning Styles........................................................................38 vi

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Studies Involving High School Students................................................38 Studies Involving Post-Secondary Students...........................................40 Socioeconomic Status..........................................................................................44 Presage Variables........................................................................................................48 Chapter Summary.......................................................................................................48 3 METHODS.................................................................................................................50 Research Design.........................................................................................................51 Procedures...................................................................................................................54 Population...................................................................................................................55 Sample Size................................................................................................................56 Instrumentation...........................................................................................................57 Unit of Instruction Plans.............................................................................................57 Content Knowledge Achievement Assessment Instruments......................................58 Learning Styles Inventory...........................................................................................58 Science Process Skill Assessment Instrument............................................................58 Treatment Delivery Analysis Scoresheet....................................................................59 Analysis of Data.........................................................................................................59 Chapter Summary.......................................................................................................60 4 RESULTS AND DISCUSSION.................................................................................62 Objective One: Describe the Learning Styles, Ethnicity, and Other Demographic Characteristics of Participants in this Study..........................................................66 Grade Level.........................................................................................................66 Ethnicity..............................................................................................................67 Gender.................................................................................................................68 Learning Style.....................................................................................................68 Content Knowledge Achievement.......................................................................71 Science Process Skill...........................................................................................74 Relationships Between Variables........................................................................77 Objective Two: Describe the Variance in Content Knowledge Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics................79 Objective Three: Describe the Variance in Science Process Skill Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics.80 Hypothesis Tests.........................................................................................................81 Tests of Assumptions of Multivariate Analysis of Covariance...........................81 Normality.....................................................................................................82 Homoscedasticity.........................................................................................82 Multivariate Test of Effects.................................................................................83 Effect of Treatment..............................................................................................83 Effects of Learning Style.....................................................................................84 Effects of Demographic Variables......................................................................85 Effects of Interaction of Variables......................................................................85 Test of Hypotheses.....................................................................................................85 Hypotheses Related to Content Knowledge Gain...............................................86 vii

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HO 1 : There is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach................86 HO 2 : There is no difference in the content knowledge gain scores of agricultural education students of different learning styles....................86 HO 3 : There is no difference in the content knowledge gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach..................................................................................................87 Hypotheses Related to Science Process Skill Gain.............................................88 HO 4 : There is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach................88 HO 5 : There is no difference in the science process skill gain scores of agricultural education students of different learning styles....................88 HO 6 : There is no difference in the science process skill gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach..................................................................................................88 Summary.....................................................................................................................89 5 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS.............................91 Objectives...................................................................................................................91 Null Hypotheses..........................................................................................................92 Methods......................................................................................................................92 Summary of Findings.................................................................................................94 Objective One......................................................................................................95 Objective Two.....................................................................................................97 Objective Three...................................................................................................97 Null Hypothesis One...........................................................................................97 Null Hypothesis Two...........................................................................................98 Null Hypothesis Three.........................................................................................98 Null Hypothesis Four..........................................................................................99 Null Hypothesis Five...........................................................................................99 Null Hypothesis Six.............................................................................................99 Conclusions...............................................................................................................100 Discussion and Implications.....................................................................................101 Objective One:...................................................................................................101 Conclusion:.................................................................................................101 Objective Two:..................................................................................................103 Conclusion:.................................................................................................103 Objective Three:................................................................................................104 Conclusion:.................................................................................................104 Hypotheses Related to Content Knowledge Gain.............................................105 Null Hypothesis One:.................................................................................105 Conclusion:.................................................................................................105 viii

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Null Hypothesis Two:................................................................................105 Conclusion:.................................................................................................106 Null Hypothesis Three:..............................................................................106 Conclusion:.................................................................................................106 Hypotheses Related to Science Process Skill Gain...........................................108 Null Hypothesis Four:................................................................................108 Conclusion:.................................................................................................108 Null Hypothesis Five:.................................................................................108 Conclusion:.................................................................................................108 Null Hypothesis Six:..................................................................................108 Conclusion:.................................................................................................108 Recommendations for Practitioners..........................................................................110 Recommendations for Further Research..................................................................110 APPENDIX A TREATMENT DELIVERY ANALYSIS SCORESHEETS....................................113 Subject Matter Approach..........................................................................................113 Prescriptive Laboratory Approach............................................................................114 Investigative Laboratory Approach..........................................................................115 B INSTRUCTIONAL PLANS.....................................................................................116 Subject Matter Approach..........................................................................................116 Prescriptive Laboratory Approach............................................................................137 Investigative laboratory Approach...........................................................................190 C CONTENT KNOWLEDGE PRETEST...................................................................242 D CONTENT KNOWLEDGE POSTTEST.................................................................250 E ANSWER KEY TO CONTENT KNOWLEDGE INSTRUMENTS.......................258 F STUDENT DEMOGRAPHIC INFORMATION SHEET.......................................260 G IRB APPROVAL......................................................................................................261 H INITIAL EMAIL TO PARTCIPATING TEACHERS............................................262 I OUTLINE FOR VIDEO TAPED TEACHER INSTRUCTIONS............................263 LIST OF REFERENCES.................................................................................................266 BIOGRAPHICAL SKETCH...........................................................................................276 ix

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LIST OF TABLES Table page 2-1 Basic and Integrated Science Process Skills............................................................32 4-1 Study Treatment Group Membership Totals............................................................64 4-2 Response Rates for Data Collection Components....................................................65 4-3 Post-Hoc Instrument Reliability...............................................................................66 4-4 Average Length of Treatment..................................................................................66 4-5 Participant Grade Level............................................................................................67 4-6 Participant Ethnicity.................................................................................................68 4-7 Participant Gender Distribution...............................................................................68 4-8 Participant Learning Style Distribution by Treatment Group..................................70 4-9 Participant Learning Style Distribution by Grade level...........................................71 4-10 Participant Learning Style Distribution by Gender..................................................71 4-11 Instrument Scores by Treatment Group...................................................................72 4-12 Correlations Between Variables...............................................................................78 4-13 Backward Regression Analysis to Predict Content Knowledge Gain Scores..........80 4-14 Backward Regression Analysis to Predict Science Process Skill Gain Scores........81 4-15 Univariate Analysis of Treatment Effects................................................................84 4-16 Content Knowledge Gain Score Pairwise Comparisons..........................................84 4-17 Science Process Skill Gain Score Pairwise Comparisons........................................84 4-18 Univariate Analysis of Learning Style Effects.........................................................85 4-19 Multivariate Analysis of Demographic Variable Effects.........................................85 x

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4-20 Mean Gain Scores by Treatment..............................................................................86 4-21 Mean Gain Scores by Learning Style.......................................................................87 4-22 Mean Content Knowledge Gain Scores by Treatment Across Learning Styles......87 4-23 Mean Science Process Skill Gain Scores by Treatment Across Learning Styles....89 xi

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LIST OF FIGURES Figure page 2-1. Conceptual Model for the Study of Classroom Teaching........................................15 2-2. Rosenshines Model of Effective Instruction...........................................................25 2-3. Kolbs Model of Experiential Learning...................................................................28 4-1. Distribution of Participant Grade Level...................................................................67 4-2. GEFT Score Interpretation Guidelines.....................................................................69 4-3. GEFT Score Distribution.........................................................................................69 4-4. Learning Styles by Treatment Group.......................................................................70 4-5. Distribution of Participant Content Knowledge Achievement Pretest Scores.........73 4-6. Distribution of Participant Content Achievement Posttest Scores...........................73 4-7. Distribution of Participant Content Knowledge Gain Scores..................................74 4-8. Distribution of Participant Science Process Skill Pretest Scores.............................75 4-9. Distribution of Participant Science Process Skill Posttest Scores............................76 4-10. Distribution of Participant Science Process Skill Gain Scores................................76 xii

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Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy EFFECTS OF INVESTIGATIVE LABORATORY INTEGRATION ON STUDENT CONTENT KNOWLEDGE AND SCIENCE PROCESS SKILL ACHIEVEMENT ACROSS LEARNING STYLES By Brian Eugene Myers May 2004 Chair: James E. Dyer Major Department: Agricultural Education and Communication The purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill achievement across learning styles, gender, and ethnicity. The independent variable in this study was the teaching method used in the agricultural education classes. The treatment groups utilized one of three levels of treatment: the subject matter approach without laboratory experimentation, subject matter approach with prescriptive laboratory experimentation, and subject matter approach with investigative laboratory experimentation. Characteristics that were treated as antecedent variables were student learning style, ethnicity, and gender. Covariates were used to adjust group means in order to compensate for previous knowledge of the subject matter. This study was conducted using a quasi-experimental design referred to as nonequivalent control group design. A purposively selected sample based upon the ability of the teacher to effectively xiii

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deliver all three teaching approach treatments was selected from the population of students enrolled in an introductory agriscience course in Florida. Regression analyses were used to develop separate prediction models for content knowledge achievement and science process skill achievement. It was reported that learning style, teaching method, ethnicity, content knowledge pretest scores, and science process skill pretest scores accounted for 33% of the variance in content knowledge gain score. It was also reported that learning style, gender, teaching method, science process skill pretest scores, and content knowledge pretest scores accounted for 36% of the variance in science process skill gain score. Multivariate analyses of covariance were conducted to determine the influence of the teaching method and learning style. Significant differences in content knowledge and science process skill gain scores were reported. Those students taught using the subject matter approach or the investigative laboratory approach were reported as having higher content knowledge and science process skill gain scores than students taught using the prescriptive laboratory approach. Participants in this study tended to white males in the ninth grade with a field-dependent learning style. Based on these findings, recommendations for practitioners and researchers were given. xiv

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CHAPTER 1 INTRODUCTION The idea that teaching involves both art and science has become more generally agreed upon by those in the education profession (Berliner, 1987). The practitioner of this somewhat paradoxical skill requires preparation and practice to become a master at this craft. Within the profession of agricultural education, an additional, somewhat contradictory, dialogue is occurring. This discussion is attempting to answer the question, Is agricultural education vocational or academic? The language found in the Smith-Hughes Act supports the contention of the vocational nature of the profession. This act, passed in 1917, defined agricultural education as a vocational subject matter (Hillison, 1996). Phipps and Osborne (1988) opined that one of the objectives of a comprehensive program of agricultural education is to assist present and prospective workers in agricultural occupations. This adds credence to the vocational side of the debate. However, since this text was written fifteen years ago, has the nature of agricultural education changed? Phipps and Osborne (1988) further suggested that promoting meaningful and practical applications of the content of other subject matter areas, such as science and mathematics, is also an objective of the comprehensive agricultural education program. This clearly supports the idea of agricultural education as an academic subject. Additional support for this claim is found in the Hatch Act. This act, passed 30 years 1

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2 prior to the Smith-Hughes Act, emphasized the scientific roots of agriculture, and thus aligned its study with that of other academic subjects (Hillison, 1996). So, is agricultural education vocational or academic? The answer may be that it is both. In its report, the Committee on Agricultural Education in Secondary Schools (National Research Council, 1988) called for the curriculum of agricultural education programs to expand. The emphasis of this expansion was greater inclusion of scientific subject matter into the curriculum. This expansion was not a call to completely abandon agricultural educations vocational past, rather the report called for the teaching of science through agriculture (p. 5). Within this new and broadened curriculum, programs were still expected to prepare students for current and future career opportunities in agriculture. The scientific literacy needs of individuals entering careers in agriculture, like all careers, are increasing in importance. Employees in todays job market need to know how to learn, reason, think creatively, make decisions, and solve problems. Science education and agriscience education can contribute in an essential way to the development of these skills in our students (National Academy of Science, 1996). An additional reason for the integration of science-based concepts into the agricultural education curriculum involves the recruitment of students into agricultural education programs. Myers, Dyer, and Breja (2003) identified revising the curriculum to include science-based agriculture concepts as one of the most successful recruitment strategies employed by successful secondary agricultural education teachers. By helping to recruit and retain students into agricultural education programs, the mandate of

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3 increasing the number of students who receive education in and about agriculture can better be accomplished (National Research Council, 1988). Statement of the Problem With the need for the inclusion of science-based concepts into the agricultural education curriculum, new methods for teaching these materials need to be investigated. The science education literature tells us that shifting to an emphasis on active science learning requires a shift away from traditional teaching methods (National Academy of Science, 1996). One of the more commonly used texts on teaching methods in agricultural education is Methods of Teaching Agriculture (Newcomb, McCracken, Warmbrod, & Whittington, 2004). Within this text, the authors describe the major areas which constitute the subject matter to be taught in agricultural education as agricultural production, agricultural supplies and services, agricultural mechanics, agricultural products, ornamental horticulture, agricultural resources, and forestry. The teaching methods espoused in this text focus on how to most effectively teach material in these content areas. However, there is no mention of how effective these techniques are at teaching science-based agriculture lessons. Since the 1988 call by the National Research Council, there has been a proliferation of agriscience based texts for use in middle and high school agricultural education programs (Buriak & Osborne, 1996; Cooper & Burton, 2002; Herren, 2002; Osborne, 1994). However, little research has been conducted in the field of agricultural education to determine how to best utilize these new materials. In their book sponsored by the National Research Council, How People Learn, Bransford, Brown, and Cocking (2000) surmised that a major goal of teaching is to

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4 prepare students to be able to adapt knowledge to various problems and settings. The authors identified several key features that teachers should employ in their lesson planning to best facilitate the learning process in their students. The first of these features is that information should be taught within multiple contexts (Bransford et al., 2000). By teaching information in this manner, students are more readily able to transfer that knowledge into different situations. Agriculture is one such context in which science, mathematics, reading, and technology subject matter can be taught (National Research Council, 1988). Bransford et al. (2000) submitted that increasing student time on task and student activity in and of itself is not an effective means of increasing student learning. They stated that hands-on activities can be a powerful way to ground emergent knowledge, but they do not alone evoke the underlying conceptual understandings that aid generalization (p. 22). This idea was addressed in the National Science Education Standards (National Academy of Science, 1996). The Standards state clearly that Hands-on activities, while essential, are not enough. Students must have minds-on experiences as well (pg. 2). To evoke understanding, activities should be integrated into the curriculum to allow students to make their knowledge on the subject explicit. Students must then engage in active mental struggling with how to connect this prior knowledge with the new experiences encountered in integrated activities (Clough, 2002). A common teaching strategy used by classroom teachers in both science and agricultural education is laboratory activities. However, laboratory activities often fail to engage students in the mental struggle suggested by Clough (2002). Classroom

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5 experiments bear little resemblance to real experiments (American Association for the Advancement of Science, 1993). The American Association for the Advancement of Science (AAAS) laments its concern over this trend of cookbook laboratory activities in its publication Benchmarks for Science Literacy. [In cookbook activities] The question to be investigated is decided by the teacher, not the investigators; what apparatus to use, what data to collect, and how to organize the data are also decided by the teacher (or lab manual); . the results are not presented to other investigators for criticism; and, to top it off, the correct answer is known ahead of time. (p. 9) This group continues to state that teachers and curriculum developers should eliminate the mechanical, recipe-following aspects (p. 9) of these laboratory activities. The elimination of these aspects of classroom laboratory activities does not mean that all classroom experiments must be conducted without teacher guidance and direction. As Clough (2002) noted, teachers are too busy to develop and implement every laboratory experiment used in their classrooms to meet the standards set by the AAAS. However, traditional prescriptive laboratory activities that have been used in the past and are commonly provided by textbook publishers can be modified to allow more student investigation. In addressing this issue, Clark, Clough, and Berg (2000) state, In rethinking laboratory activities, too often a false dichotomy is presented to teachers that students must either passively follow a cookbook laboratory procedure or, at the other extreme, investigate a question of their own choosing. These extremes miss the large and fertile middle ground that is typically more pedagogically sound than either end of the continuum. (p. 40) It is this middle ground described by Clark, Clough, and Berg that investigative laboratory activities attempt to address. The integration of investigative laboratory activities combines the aspects of traditional laboratory experiment modification espoused by Clark, Clough, and Berg (2000), the mental engagement prescribed by Bransford et al. (2000), and the foundations

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6 of experiential learning promoted by Kolb (1984). Kolb stated that students should come into contact with a concrete experience when introduced to new information. This experience provides them with a reference point upon which to reflect as they travel through the educational process. Additionally, investigative activity integration focuses on student inquiry as a learning method. The Standards (1996) state that inquiry is key to student understanding of science. Inquiry is a multifaceted activity that involves making observations; posing questions; examining books and other sources of information to see what is already known; planning investigations; reviewing what is already known in light of experimental evidence; using tools to gather, analyze, and interpret data; proposing answers, explanations, and predictions; and communicating the results. Inquiry requires identification of assumptions, use of critical and logical thinking, and consideration of alternative explanations. (p. 23) The foundations of investigative activity integration are supported by the American Association for the Advancement of Science. The AAAS (1990b) states that students are better able to learn about things that are tangible and directly accessible to their senses. The AAAS continues to suggest that concrete experiences that occur within a context are most effective. This contextual structure can be provided by teaching science concepts in the context of agriculture (National Research Council, 1988). The Standards (1996) do offer a caution, indicating that conducting hands-on activities does not guarantee inquiry. Additionally, hands-on activities are not the only way in which students can engage in inquiry. What is key, however, is that inquiry activities are conducted to answer authentic questions generated from student experience (National Academy of Science, 1996). A review of research conducted in agricultural education revealed results that are inconclusive, at best, in identifying the most effective teaching methods to be used by

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7 teachers for science-based agriculture lessons. Moreover, most research dealing with student content knowledge achievement in agricultural education has relied on descriptive and causal-comparative methods (Edwards, 2003). Slavin (2003) stated that more studies utilizing experimental designs are needed in this area. Furthermore, a review of research produced few studies that addressed the effect of investigative activity integration on student content knowledge achievement or science process skill development. To address the concerns of Edwards (2003) and Slavin (2003) regarding research of this type, this study was conducted using a quasi-experimental design. The problem addressed in this research contained two parts: limited agriscience content knowledge achievement of some agriscience students, little empirical evidence regarding the most effective strategies for teaching agriscience concepts This study investigated the effect of investigative laboratory integration on content knowledge achievement and science process skill development of students of differing learning styles. This study sought to determine if integrating investigative laboratories in a manner that would encourage students to engage mentally in the activity at a higher level would significantly affect content knowledge achievement and science process skill proficiency level. Findings from this study could provide an important addition to the knowledge base. This information could be utilized by both agricultural education teachers in middle school and high school settings, as well as by teacher educators at colleges and universities, in the preparation of teachers.

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8 Purpose of the Study The primary purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill development across different learning styles. The specific objectives and hypotheses of this research were as follows: Statement of Objectives 1. Describe the learning styles, ethnicity, and other demographic characteristics of participants in this study. 2. Describe the variance in content knowledge gain score attributed to learning styles, ethnicity, and other demographic characteristics. 3. Describe the variance in science process skill gain score attributed to learning styles, ethnicity, and other demographic characteristics. Statement of Hypotheses For the purpose of statistical analysis, the research questions were posed as null hypotheses. All null hypotheses were tested at the .05 level of significance. HO 1 : There is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches. HO 2 : There is no difference in the content knowledge gain scores of agricultural education students of various learning styles. HO 3 : There is no difference in the content knowledge gain scores of agricultural education students of varying learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 4 : There is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 5 : There is no difference in the science process skill gain scores of agricultural education students of various learning styles. HO 6 : There is no difference in the science process skill gain scores of agricultural education students of varying learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach.

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9 Definition of Terms For the purpose of this study, the following terms were defined operationally: Agricultural education: a term used to represent the profession of teaching students about all areas of agriculture from production to consumption. In most cases this term was used to represent formal instruction in agriculture conducted in a middle school or secondary school settings. Agriscience Foundations: the first course in most secondary Agriscience and Natural Resources programs in the State of Florida. This course satisfies a requirement of a science with a laboratory component towards graduation. Content Knowledge Achievement: the number of correct responses on the content knowledge achievement test administered immediately after the treatment. Ethnicity: this student characteristic was categorized as White, Black, and Hispanic. Inquiry-based science: an approach used for teaching and learning science that stresses the engagement of students in the process of finding out about natural phenomena, constructing their knowledge of scientific conceptions, and reflecting on the degree to which the learning corresponds to authentic science (Kenyon, 2003). Investigative laboratory exercise: laboratory exercises in which the students develop the procedures to follow to investigate a scientific question. The classroom teacher provides guidance and advice, but does not inform students of expected outcomes prior to student completion of the exercise. Learning style: the individuals preferred method of perception and processing. Leaning style refers to the way each person perceives, sorts, absorbs, processes, and retains information (Dunn, 1984; Dyer, 1995). Determined by Group Embedded Figures Test (GEFT) (Witkin, Oltman, Raskin, & Karp, 1971) scores. Classified as field-dependent, field-neutral, or field-independent. Prescriptive laboratory exercise: laboratory exercises in which the teacher provides clear step-by-step instructions to the students. In addition, the teacher provides information as to the expected outcome of the exercise prior to student completion of the exercise. Retention of content knowledge: the number of correct responses on the content knowledge retention test administered four weeks after the treatment. Science process skills: ability to plan, conduct, and interpret results from scientific investigation. Determined by Test of Integrated Process Skills (TIPS) (Dillashaw

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10 & Okey, 1980). Specifically, the skills of observing, comparing, classifying, quantifying, measuring, experimenting, inferring, and predicting are assessed. Subject matter approach: an expository teaching strategy in which the teacher assumes full responsibility for determining what and how subject matter will be learned as characterized by Flowers (1986). Rosenshine and Stevens (1986) suggest a six step model for this approach that includes a daily review, presentation of new material, guided student practice, feedback, independent student practice, and reviews (evaluation). Limitations of the Study The conclusions and implications drawn from this study are subject to the following limitations: The data are limited to those obtained from purposively selected Florida agricultural education students. Teachers were purposively selected. Therefore, generalization of the results of this study to other groups will be limited to the degree to which those groups match the population and sample used in this study. The results are limited to the extent that they reflect only one unit of instruction common to all agriculture programs included in the sample. Assumptions of the Study The following assumptions were made for the purposes of this study: The students involved in this study performed to the best of their ability. Learning styles and science process skills of students can be accurately identified using written assessments. Chapter Summary The primary purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill development across different learning styles. This chapter provided a description of the rationale for evaluating the effects of investigative laboratory integration in secondary agricultural education courses.

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11 The significance and justification of the study was also discussed. The findings contained in the literature base are inconclusive as to the best methods in which to teach science-based agricultural education content. The information gained from this study should be of value both to practicing agricultural education teachers and teacher educators. By understanding ways in which to best integrate science into the agricultural education curriculum, the profession can better position itself with other content areas to assist students to succeed not only on state mandated examinations, but in life in general. Additionally, for agricultural education to remain a viable and relevant component of public education, the profession must show how the curriculum addresses the academic standards set by many state departments of education (Shinn, 2002). By integrating science concepts, which address the science standards, agricultural education is better able to secure its place at the educational policy and funding table. The research objectives were also included in this chapter. The specific objectives and hypotheses of this research were reported as follows: 1. Describe the learning styles, ethnicity, and other demographic characteristics of participants in this study. 2. Describe the variance in content knowledge gain score attributed to learning styles, ethnicity, and other demographic characteristics. 3. Describe the variance in science process skill gain score attributed to learning styles, ethnicity, and other demographic characteristics. HO 1 : There is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 2 : There is no difference in the content knowledge gain scores of agricultural education students of various learning styles. HO 3 : There is no difference in the content knowledge gain scores of agricultural education students of varying learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach.

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12 HO 4 : There is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 5 : There is no difference in the science process skill gain scores of agricultural education students of various learning styles. HO 6 : There is no difference in the science process skill gain scores of agricultural education students of varying learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Chapter 2 will describe the theoretical and conceptual framework of this study. Furthermore, the empirical research contained within the literature base of agriculture education relevant to this study will be described.

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CHAPTER 2 REVIEW OF THE LITERATURE Chapter 1 described the rationale for evaluating the effects of investigative laboratory integration in secondary agricultural education courses. The primary purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill development across different learning styles. This chapter describes the theoretical and conceptual frameworks, and delineates the empirical research relevant to this study. The review of the literature base focused on textbooks, refereed and non-refereed publications in agricultural and science education, and articles appearing in the ERIC Documentation Reproduction Service. Included in this chapter is a review of literature and research pertaining to the following: context variables o learning style o gender o ethnicity process variables o subject matter approach o experiential learning o inquiry-based approach presage variables product variables o content knowledge achievement o science process skills Theoretical Model of the Teaching and Learning Process Mitzel (1960) proposed that teaching effectiveness criteria could be classified according to goal-proximity as product criteria, process criteria, or presage criteria. The 13

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14 Mitzel model (Dunkin & Biddle, 1974) laid the foundation for evaluating teaching effectiveness. This model provided the theoretical framework for the current study (Figure 2-1). Building upon the teaching effectiveness criteria suggested by Mitzel, the model for the study of classroom teaching identifies variables affecting the teaching-learning process and categorizes them into four groups. These groups are context variables, presage variables, process variables, and product variables. Context variables, as defined by Dunkin and Biddle (1974), are the conditions to which the teacher must adjust. These are characteristics of the environment about which little can be done. Contained within the category of context variables are four sub-categories of pupil formative experiences, pupil properties, school and community context, and classroom context. Examples of the first sub-category, pupil formative experiences, could be socioeconomic status, age, and gender. Pupil properties could include ability, knowledge, and attitudes. The sub-categories of school and community context and classroom context include the size, ethnic composition, and equipment of each of the respective settings. Presage variables are those characteristics of teachers that may be examined for their effects on the teaching and learning process. Mitzel (1960) called these pseudo criteria. He continued by saying that these were criteria that are from a logical standpoint completely removed from the goals of education (p. 1484). There are three

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Pupil Formative Experiences socioeconomic status age gender Context Variables Pupil Properties abilities knowledge attitudes School/Community Contexts climate ethnic composition school size bussing Classroom Context class size textbooks education technology Presage Variables Teacher Formative Experiences socioeconomic status age gender Teacher Training Experiences university attended training program features practice teaching experiences Teacher Properties teaching skills intelligence motivations personality traits Process Variables The Classroom Pupil Classroom Behavior Teacher Classroom Behavior Observable Changes in Pupil Behavior Product Variables Immediate Pupil Growth subject matter learning attitudes toward subject growth of other skills Long-term Pupil Effects adult personality professional or occupational skills 15 Figure 2-1. Conceptual Model for the Study of Classroom Teaching (Dunkin & Biddle, 1974)

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16 sub-categories of presage variables. They are teacher formative experiences, teacher training experiences, and teacher properties. Teacher formative experiences are the same characteristics as those listed under the pupil formative experiences identified in the context variable. Examples are the teachers socioeconomic status, age, and gender. Experiences such as the college or university attended by the teacher, courses taken, experiences during practice teaching, and in-service and postgraduate education comprise examples of items that could be found in the teacher training experiences sub-category. Items within this sub-category are the most often studied variables (Dunkin & Biddle, 1974). The final sub-category of presage variable is teacher properties. These are measurable personality characteristics. Examples of items included in this sub-category are teaching skills, intelligence, and motivation. Process variables include the actual activities of classroom teaching. This variable consists of the classroom behavior of both the teacher and the pupil. The final variable identified in this model is product variables. These are the outcomes of teaching. These are changes that come about in pupils as a result of their involvement in classroom activities with teachers and other pupils. Product variables represent a change in student behavior. Examples of product variables include a change in learning, attitudes, skill development, or adult personality development (Dyer, 1995). These outcomes can be grouped into two categories. The first is immediate pupil growth. This involves the areas of subject-matter learning, attitudes toward the subject, and growth of other skills. The second category is long-term pupil effects. Examples in this area are professional or occupational skills (Dunkin & Biddle, 1974).

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17 Flowers (1986) stated that researchers must address all of these variables in any study involving classroom teaching. He stated that while the researcher may select and examine specific product variables of interest, the other variables must be addressed by the researcher and controlled by either research design or statistical methods. Product Variables The product variables of interest in this study are student content knowledge achievement and science process skill development. Referring to Mitzels model, student content knowledge achievement and science process skill development are measures of immediate pupil growth. Whereas retention of content knowledge would be an example included in the long term pupil effects category of product variables (Dunkin & Biddle, 1974). All of these variables have been observed in previous studies in which contrasting teaching methods were examined (Dyer, 1995; Flowers, 1986). Although these variables are clearly supported by Mitzels model, and have been researched in a limited number of studies, the majority of studies in the area of agriscience have only examined teacher attitudes and perceptions (Balschweid & Thompson, 1999; Connors & Elliot, 1994; Dyer & Osborne, 1999b; Layfield, Minor, & Waldvogel, 2001; Newman & Johnson, 1993; Peasley & Henderson, 1992; Thompson, 1998; Thompson & Balschweid, 1999; Welton, Harbstreit, & Borchers, 1994). Student Content Knowledge Achievement Boone and Newcomb (1990) investigated and compared the effects of problem solving and subject matter teaching approaches on student content knowledge achievement. This quasi-experimental design included 121 freshmen students enrolled in agriculture courses in seven Ohio high schools. Teachers of these classes were purposively selected for their ability to use the problem solving approach. The

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18 researchers reported no significant difference in student content knowledge achievement or retention between the students taught using the various teaching approaches. Dyer and Osborne (1996a) also compared the relative effectiveness of the problem solving approach and the subject matter approach. This study involved six purposively selected teachers who were determined capable of demonstrating both teaching approaches. Within this group of teachers, treatments were randomly assigned to intact classes. The sample included 16 classes with 258 students. The researchers reported that for field-neutral learners, the problem solving approach was found to be more effective in increasing student content knowledge achievement than the subject matter approach. However, no significant difference in content knowledge achievement was reported for field-dependent or field-independent learners exposed to the two teaching approaches. In a study of student performance through the use of active learning, it was reported that such strategies resulted in improved student attitude toward the subject matter (Blakey, Larvenz, McKee, & Thomas, 2000). However, no change was reported in student content knowledge achievement, as measured by test score. This study was conducted with a sample of fourteen general music classes in western Illinois. Contained within this sample were six 7th grade classes and eight 8th grade classes. The active learning methods and strategies of graphic organizers, cooperative learning, role playing, and think-pair-share were used as the active learning treatment in this study. In a study includeing seven introductory agriscience classes enrolling primarily ninth grade students (n = 132) from five different school districts, Johnson, Wardlow, and Franklin (1998) reported no significant differences in either immediate or delayed cognitive scores between the use of worksheets or hands-on activities. The study further

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19 reported no significant interaction between the factors of method or gender. However, significant differences were reported on both immediate and delayed cognitive score based on gender. The researchers reported that females tended to score higher than males on the posttest. This study utilized a randomized post-test-only experiential design with a counter-balanced internal replication. Connors and Elliot (1995) reported no significant difference in content knowledge achievement, based on a standardized science test, between students who had and had not enrolled in agriscience and natural resources courses. This study found that overall grade point average and the number of science credits completed explained the largest portion of the variance in science achievement score with correlation coefficients of .57 and .49 respectfully. Four high schools which offered agriscience and natural resource classes in Michigan were randomly selected to participate in this study. The sample included 156 senior high school students. Roegge and Russell (1990) investigated the effect of incorporating biological principles into a unit of instruction in an agriculture course. The study consisted of 104 students in nine schools. A pretest-posttest control group design was used. A significant difference was reported in both overall content knowledge achievement and applied biology achievement, with students in the integrated approach group scoring higher. Chiasson and Burnett (2001) investigated the effect of agriscience courses on science content knowledge achievement of high school students in Louisiana. This was a census study that included all 11 th grade students enrolled in public schools in the state. The researchers reported that agriscience students tended to earn higher scores than non-agriscience students on the science portion of the Louisiana exit examination. The

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20 researchers continued by reporting that agriscience students scored as high or higher on four of the five science domain sub-scales. Also, agriscience students were more likely to pass the examination than non-agriculture students. Science Process Skill Dillashaw and Okey (1980) developed and tested an instrument to assess the science process skills associated with planning, conducting, and interpreting results from investigations. Collectively these are often referred to as the integrated science processes. Specifically these include skills such as formulating hypotheses, operationally defining, controlling, and manipulating variables, planning investigations, and interpreting data (Livermore, 1964). The instrument was first field tested with samples of approximately 100 students each from grades 7, 9, and 11 in two schools. Revisions were made and the instrument was field tested with a sample of over 700 students from the same grade levels as the first test. This instrument was designed to develop a measure of integrated process skill achievement referenced to a specific set of objectives, and was found to be a valid and reliable measure of science process skill achievement for students in the 7 th to 12 th grade (Dillashaw & Okey, 1980). Germann (1989) investigated the effect of the directed-inquiry approach on science process skills and scientific problem solving. The sample for this study included four sections of 9 th and 10 th grade general biology. Students were grouped by academic ability, with the experimental group consisting of average ability students and the comparison group consisting of above-average ability students. The researcher reported that the use of a directed-inquiry approach had no significant effect on the learning of science process skills or on cognitive development.

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21 Burchfield and Gifford (1995) investigated the development of science process skills of community college students by using computer-assisted instruction. The 92 participants in this study were enrolled in General Biology I for Science Majors at a small, rural community college in the southeastern United States. The study found no significant difference between the mean gain in science process skill proficiency between students instructed with the traditional treatment or those receiving computer-assisted instruction. Neither, student academic aptitude, as measured by scores on the Enhanced American College Testing Assessment, nor gender were found to be factors influencing science process skill development for either treatment. Mabie and Baker (1996) conducted a study to explore the impact of two types of agriculturally-oriented experiential instructional strategies on science process skills. In this study, three classrooms in Los Angeles consisting of fifth and sixth grade students were observed. A total of 147 students participated in this study. The findings of this study indicated that participation in agriculturally-oriented experiential activities positively impacts the development of science process skills. Participation in experiential activities assisted students in their ability to observe, communicate, compare, relate, order and infer. Downing, Filer, and Chamberlain (1997) examined if there was a relationship between preservice elementary teachers competency in science process skills and attitudes toward the field of science. This study included a sample of 46 preservice elementary teachers enrolled in a mathematics and science methods course just prior to student teaching. This study found a moderately positive correlation (r = .39) between

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22 the preservice teachers competency levels of science process skill and attitudes toward science. Osborne (2000) examined the effects of level of openness in agriscience experiments on student achievement and understanding of science process skills. This quasi-experimental study used a nonequivalent control group design. The sample included 150 students from 14 schools. Nearly all students in the sample were 15 or 16 years of age. This study found that the students who participated in the prescriptive laboratories developed higher levels of science process skills and achievement than those students conducting investigative laboratory exercises. However, it was also discovered that in general all the students in the agricultural education courses had very low science process skill scores as measured by the Test of Integrated Process Skills. Osborne recommended that a follow-up study be completed to investigate the effects of learning style on science achievement and process skill proficiency. Process Variables The process variables examined in this study were the teaching methods used in the treatment conditions. This study involved three treatment groups utilizing various teaching methods in varying capacities. Treatments differed on the approach to teaching agriscience laboratory exercises. The teaching methods that served as the foundation for these methods were the subject matter approach, experiential learning, and inquiry-based instruction. Subject Matter Approach The subject matter approach to teaching is a commonly used teaching method in agricultural education (Flowers, 1986). This method is also commonly used as the control treatment in studies investigating the effects of another teaching method, most

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23 often, the problem solving approach (Boone, 1988; Dyer, 1995; Flowers, 1986). The subject matter approach is a teacher-centered approach. In utilizing this approach, the teacher selects the content to be studied, explains the importance or relevance of the content, and selects the learning activities to be used to present the information. Typically the content to be delivered is organized around specific, often behaviorist-learning objectives (Mager, 1997). Flowers (1986) compared the effectiveness of the problem solving approach to the subject matter approach. His study consisted of 126 agriculture students from eight high schools enrolled in an introductory level agriculture course. In this study each teacher taught two courses, one using the problem solving approach and the other using the subject matter approach. Flowers reported no significant difference in student content knowledge achievement, cognitive achievement, retention, attitude, or time required to complete instruction. Boone (1988) also investigated the effects of teaching approach on student content knowledge achievement, retention of content knowledge, instructional time, and student attitude toward instruction. Similar to Flowers (1986), the teaching approaches tested in this study were subject matter approach and problem solving approach. This study utilized a quasi-experimental counterbalance design as described by Campbell and Stanley (1963). Purposively selected teachers taught two instructional units. One unit was taught using the problem solving approach and the second taught using the subject matter approach. The accessible population for this study was 121 freshman students enrolled in production agriculture classes in Ohio. It was reported that student content knowledge achievement varied according to timing of the unit and instructional approach.

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24 Students taught first with the problem solving approach and then the subject matter approach had higher content knowledge achievement scores and higher scores on attitude toward instruction. It was further reported that both approaches required the same amount of classroom time to complete. Boone also reported that teachers in the study did not fully incorporate the problem solving approach as prescribed by the researcher. Based on this, the researcher recommended that future studies investigating the problem solving approach begin with an inservice series to instruct teachers on the problem solving approach. Dyer (1995) conducted a study following similar procedures to that of Boone (1988) and Flowers (1986) with the addition of examining the effect of student learning style and instructing teachers in the proper use of both the problem solving and subject matter approaches. The sample of this quasi-experimental study consisted of 133 students from 12 classes. It was reported that the problem solving approach produced significantly higher scores in student problem solving ability across all learning styles. A significant increase in content knowledge achievement score was reported for field-neutral learners. No significant differences were detected across learning styles on retention scores. The study also reported that the majority of ninth grade students were field-dependent in their learning style. Furthermore, problem solving ability was reported to increase by grade level and was highest for field-independent learners. By synthesizing research that had been conducted in education and other related areas, Rosenshine (Rosenshine & Stevens, 1986; Rosenshine, 1987) presented a model of effective instruction (Figure 2-2) when utilizing the subject matter approach. There are six major steps in this model: (1) review previous days work, (2) present new content,

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25 (3) guided student practice, (4) feedback and correctives, (5) independent student practice, and (6) weekly and monthly reviews. In the first step of reviewing the previous days work, Rosenshine and Stevens (1986) presented two purposes for completing this step: it provides additional practice and overlearning for previously learned material, and it allows the teacher to provide corrections and reteach areas in which students are having difficulty. This step may be accomplished through questioning techniques, student peer reviews, or a short quiz. Review p revious wor k Present new content Guided student p ractice Feedback and correctives Independent student practice Weekly and monthly reviews Reteach, if needed Figure 2-2. Rosenshines Model of Effective Instruction (Rosenshine, 1987) The steps of presenting new material and student guided practice are very closely aligned according to Rosenshines (1987) model. After new material is presented and demonstrated by the teacher, guided student practice should follow (Rosenshine & Stevens, 1986). The purpose of guided practice is to check for student understanding of the concept. The teacher should reteach the material if it is determined that a substantial number of students have failed to learn the material.

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26 Following student guided practice, students should be given the opportunity to practice using the new knowledge or skill on their own. The goal is to allow students to integrate the information or skills with previous knowledge and to become automatic in their use of the information (Rosenshine & Stevens, 1986). Weekly and monthly reviews were also found to improve the learning of new material. These reviews provide a teacher with another point in which to check the students understanding of the material (Rosenshine & Stevens, 1986). Experiential Learning The experiential learning theory proposed by Kolb (1984) was built upon the foundations laid by Lewin, Dewey, and Piaget. Kolb suggested that experiential learning provides a foundation for an approach to education and learning whose theoretical basis is located with social psychology, philosophy, and cognitive psychology. Dewey (1938) opined that there is an intimate and necessary relation between the processes of actual experience and education (p. 19, 20). The idea that learning must be accompanied by some real-world experience has been built upon by several researchers. Keeton and Tate (1978) encouraged educational strategies that allowed the learner to have direct interaction with the phenomenon being studies. Merely thinking about the object or idea to be learned was not sufficient. Argyris and Schon (1974; 1978) suggested that learning through experience is essential for individual and organizational effectiveness. The importance of this type of learning experience was described by Chickering (1977) in saying that experiential learning contributes to more complex development intellectually. Learning constructed in this manner assists individuals cope with shifting developmental tasks that are brought on by rapid social change.

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27 Experiential learning theory offers a fundamentally different understanding of how individuals learn than do the behavioral theories. Thus, this different way of learning requires a new approach to teaching (Kolb, 1984). Whereas behaviorist learning theories approach ideas as fixed elements that always remain the same, Kolbs theory states that ideas are formed and re-formed through experience. In support of Kolb, Freire (1974) described the transmission of fixed content supported in the behaviorist idea of learning as the banking concept of education. He continued his criticism by suggesting that this banking of information allows the individual to extend this knowledge only as far as receiving, filing, and storing. Kolb (1984) defines learning as the process whereby knowledge is created through the transformation of experience. Knowledge results from the combination of grasping experience and transforming it. The cornerstones of Kolbs model are the four adaptive learning modes (Figure 2-3). The first of these is concrete experience. In this mode, students involve themselves fully, openly, and without bias in new experiences. The second mode is reflective observation. In this mode the student reflects on and observes their experiences from many perspectives. Next, students enter the abstract conceptualization mode. In abstract conceptualization, learners create concepts that integrate their observations into logically sound theories. The fourth mode is active experimentation. Students apply the theories developed in the abstract conceptualization mode to make decisions and solve problems. In the Kolb model, knowledge is a result of a combination of grasping experience and transforming that experience. This model suggests four different elementary forms of knowledge. Divergent knowledge is a result of experience grasped through

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28 Concrete Experience Reflective Observation Abstract Conceptualization Experimentation Grasping via APPREHENSION Grasping via COMPREHENSIONTransformation via EXTENSIONTransformation via INTENTIONAccommodativeKnowledge Divergent Knowledge Convergent Knowledge Assimilative Knowledge Active Figure 2-3. Kolbs Model of Experiential Learning (Kolb, 1984) apprehension and transformed through intention (Kolb, 1984). The idea of grasping through apprehension corresponds closely with James (1890) views of knowledge of acquaintance. Grasping through apprehension describes the knowledge of something or a familiarity with the object. The transformation via intention can be associated with Piagets idea of intellectual operations, meaning that these transformations are internalized. Assimilative knowledge is grasped through comprehension and transformed through intention (Kolb, 1984). Comprehension can be likened to James (1890) knowledge-about. Convergent knowledge is developed when experience is grasped through comprehension and transformed through extension. The final form of knowledge

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29 is accommodative knowledge. It is developed when experience is grasped by apprehension and transformed by extension (Kolb, 1984). Kolbs continuous cycle model calls for learners to be engaged in all four modes of learning, developing all four types of knowledge. Powell and Wells (2002) compared the effectiveness of three experiential teaching approaches on student science learning. Twelve fifth-grade classes with 211 students in a Colorado school district were assigned to each of three treatment groups. The researchers reported no significant differences between treatment groups suggesting that lessons adapted to meet Kolbs four stages of learning may not necessarily lead to more effective means of knowledge acquisition. Hakeem (2001) investigated the effect of experiential learning in a business statistics course. Participants in this study were undergraduate students at a regional 4-year university. A total of 213 students were randomly divided into two groups, one would be involved in experiential activities as part of the course the other would not. Hakeem reported that students who had participated in the experiential learning project had significantly higher scores on the content knowledge achievement test that measured more complicated concepts. No significant difference was found between the groups, as measured by content knowledge achievement tests, on traditional statistics techniques requiring formulas and hand computations. Schlager, Lengfelder, and Groves (1999) examined the use of experiential education as an instructional methodology for travel and tourism classes. The sample for this study included students enrolled in two graduate travel and tourism courses at a 4-year university in Ohio. The researchers reported that students in the sections that used

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30 experiential methods had a greater preference for less structured instructional methods and that these methods lead to higher motivation. Wulff-Risner and Stewart (1997) compared two experiential teaching methods on learning outcomes of 8-18 year old students. This quasi-experimental study included a sample of 98 students who participated in a workshop on horse judging in Missouri. The researchers reported that students taught in the classroom videos and pictures scored significantly higher on achievement tests for both conformation judging skills and performance judging skills than did students taught with live animals. Inquiry-based Instruction As the agricultural education profession works to expand its research base regarding teaching methods to deliver scientific concepts effectively, the work completed in this area by our colleagues in science education should be examined. The science education literature states that shifting to an emphasis of active science learning requires a shift away from traditional teaching methods (National Academy of Science, 1996). The report by the American Association for the Advancement of Science (AAAS) titled Science for All Americans (1990b) emphasized that the teaching of scientific concepts should be consistent with the nature of scientific inquiry. Furthermore, the National Science Education Standards (National Academy of Science, 1996) state that inquiry is central to learning science. The process skill approach (Chiappetta & Koballa, 2002) is one teaching method discussed in the science education literature that could be employed by agriculture teachers in the effort to teach science as inquiry. Although these process skills are not listed specifically in the National Science Education Standards (National Academy of

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31 Science, 1996), they have been integrated into the broader abilities of scientific inquiry (National Research Council, 2000). The process skill approach focuses on teaching broadly transferable abilities that are appropriate to many science disciplines and are reflective of the behavior of scientists (Padilla, 1990). Chiappetta (1997) states, the acquisition and frequent use of these skills can better equip students to solve problems, learn on their own, and appreciate science (p. 24). The science process skills can be classified as either basic or integrated (see Table 2-1). The basic science process skills are designed to provide a foundation for learning the more complex integrated science process skills (Padilla, 1990). Examples of integrated science process skills include skills such as formulating hypotheses, operationally defining, controlling, and manipulating variables, planning investigations, and interpreting data (Livermore, 1964). It is important that inquiry-based instruction be conceptualized as teaching both the content (what) and the process (how) of science (Chiappetta & Adams, 2004). Inquiry and the National Science Education Standards (National Research Council, 2000) outlines three facets of inquiry-based instruction for students to aid in their understanding to these two components of science. In this report, the authors opined that students should (1) learn the principles and concepts of science; (2) obtain reasoning and procedural skills of scientists by conducting investigations, critical thinking, and problem solving; and (3) understand how scientific knowledge is created, processed, and represented by scientists at work. One way to address these components is through the use of investigative laboratory exercises.

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32 Table 2-1 Basic and Integrated Science Process Skills Process Skill Definition Basic Skills Observing Noting the properties of objects and situations using the five senses Classifying Relating objects and events according to their properties or attributes Space/time relations Visualizing and manipulating objects and events, dealing with shapes, time, distance, and speed Using numbers Using quantitative relationships Measuring Expressing the amount of an object or substance in quantitative terms Inferring Giving an explanation for a particular object or event Predicting Forecasting a future occurrence based on past observation or the extension of data Integrated Skills Defining operationally Developing statements that present concrete descriptions of an object or event by telling one what to do or observe Formulating models Constructing images, objects, or mathematical formulas to explain ideas Controlling variables Manipulating and controlling properties that relate to situations or events for the purpose of determining causation Interpreting data Arriving at explanations, inferences, or hypotheses from data that have been graphed or placed in a table Hypothesizing Stating a tentative generalization of observations or inferences that may be used to explain a relatively larger number of events but that is subject to immediate or eventual testing by one or more experiments Experimenting Testing a hypothesis through the manipulation and control of independent variables and noting the effects on a dependent variable; interpreting and presenting results in the form of a report that others can follow to replicate the experiment Note: Adapted from Padilla (1990) An investigative laboratory exercise differs from the traditional cookbook laboratory activities in that investigative exercises allow the student to design an experiment that addresses a problem of their choosing. In traditional laboratory exercises, students are given prescribed directions to carry out activity which is designed to demonstrate the phenomena or reinforce concepts given in a lecture (Sundberg &

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33 Moncada, 1994). Thornton (1972) provided a list of characteristics common to all investigative laboratories. Students are aware that the purpose is to engage in investigation An initial series of activities prepares students to investigate In consultation with the instructor, students formulate problems and procedures Adequate time is given to repeat and/or modify experiments Students prepare written and/or oral reports Sundberg & Moncada (1994) provide three variations that can be made to the listing provided by Thornton. The first involves beginning a unit of instruction with a prescriptive or cookbook laboratory activity. Upon the completion of this exercise, students used data gathered as a starting point for further investigation. A second variation employs inquiry laboratories. Inquiry laboratories are more directed in nature than investigative laboratories as described by Thornton. In inquiry laboratories, the teacher leads students in discovery of a certain concept or relationship by posing a series of What happens if? questions. The final alternative suggested by Sundberg & Moncada is the open-inductive laboratory. This form of investigative laboratory does not include a series of activities which are designed to prepare the students to investigate. Students are given only minimal direction as to the design and procedures for their investigation. Laboratory Instruction Heins Rothenberger and Stewart (1995) investigated the effectiveness of instruction in horticulture using and not using a greenhouse experience with the traditional classroom lecture/discussion technique. This study used a cluster sampling technique and included 168 high school agricultural education students. It was reported that students who received a greenhouse laboratory experience scored significantly higher on the

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34 knowledge test. No significant difference was reported between the post-experiment attitude toward poinsettia production group scores for the two groups. Johnson, Wardlow, and Franklin (1997) utilized a posttest-only control group experimental design with a counter-balanced replication to determine the effects on cognitive achievement and attitude toward the subject matter of a hands-on activity versus a worksheet in teaching physical science principles. A purposively selected sample of 132 students from seven agricultural education classes in Arkansas constituted the sample for this study. The researchers reported no significant difference in the content knowledge achievement level of students taught with hands-on activity versus those taught with worksheets. However, a significant difference was reported between groups on attitude toward instruction. Students taught with the hands-on instruction method reported a more positive attitude. Using the same sample as the above study, Johnson, Wardlow, and Franklin (1998) reported that both hands-on and worksheet reinforcement methods were equally effective in supporting learning and retention of subject matter. However, differences on both the immediate and delayed posttests were noted for the main effect of gender. Female students scored significantly higher than did male students. Context Variables The context variables examined in this study are student learning style, science process skill, socioeconomic status, gender, and ethnicity. The researcher is aware that there is a multitude of characteristics within the environment to which the teacher must adjust. These variables were selected to be included in the study after an extensive literature review identified these as being some of the more influential characteristics that affect the product variables of interest.

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35 Learning Style Although a multitude of definitions exist for the term learning style, most definitions include at least three of the following underlying concepts: Students learn via different ways and means Learning styles are personal to the learner The way in which a person perceives and processes information (Dunn & Dunn, 1979; Gregorc, 1979; Witkin, Oltman, Raskin, & Karp, 1971) One of the first to categorize learners based on cognitive style was Jung. His categories were determined based on a persons relation to the world (introversion/extroversion), decision making (perception/judgment), perceiving (sensing/intuition), and judging (thinking/feeling) (Kolb, 1984). Another pioneering researcher who studied the cognitive-development process in great detail was Piaget. Piaget examined childrens ability to display abstract reasoning in a concrete environment (Kolb, 1984). One of the criticisms of learning style research is its lack of focus and direction (Dyer, 1995). The literature contains numerous studies on learning styles, yet the lack of consistency in the way in which learning style is measured and the terminology used to describe them has lead to a lack of utilization of this information in the classroom. Learning Styles Instrumentation Numerous forms of instrumentation can and have been used to identify individual learning style. For the purposes of this study, only instruments which have been used extensively in the agricultural education literature will be discussed. The three most commonly utilized learning style instruments in agricultural education are: Group Embedded Figures Test (GEFT) (Witkin et al., 1971) Myers-Briggs Type Indicator (MBTI) (Briggs & Myers, 1977) Learning Styles Inventory (LSI) (Kolb, 1984)

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36 Group Embedded Figures Test (GEFT) One of the simplest and most extensively examined instruments is the Group Embedded Figures Test (GEFT) (Witkin, Moore, Goodenough, & Cox, 1977; Witkin et al., 1971). This learning style instrument divides students into one of two categories: field-independent or field-dependent. Field-independent learners are more analytical in the way they perceive the world. These learners are able to provide structure and organize information on their own. This ability often leads to field-independent students requiring less teacher guidance in developing strategies to solve problems (Ronning, McCurdy, & Ballinger, 1984). It was reported by Witkin, Oltman, Raskin, and Karp (1971) that at approximately age 24 individuals begin a process of becoming more field-dependent. In addition to being age-related, Witkin et al. reported that males are more likely to be field-independent than females. However, in agricultural education several studies have shown that the majority of females in this profession tend to be field-independent (Cano & Garton, 1994b; Garton, Spain, Lamberson, & Spiers, 1999; Raven, Cano, Garton, & Shelhamer, 1993; Rudd, Baker, & Hoover, 2000; Rudd, Baker, & Hoover, 1998; Whittington & Raven, 1995). In contrast, there have also been several studies to support the gender relationship stated by Witkin et al. (Dyer & Osborne, 1996a, 1996b; Moore & Dyer, 2002; Torres & Cano, 1994). Individuals classified as field-dependent by the GEFT are normally more social in their nature. They have a global perception of the world which often leads to these individuals finding it more difficult to solve problems (Ronning et al., 1984). This is often a cause of field-dependent learners needing to have structure and organization

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37 provided for them by an external source. This could lead to students of this learning style requiring a more student-centered teaching approach and more direction on how to structure and solve agriscience problems. Myers-Briggs Type Indicator A second instrument often used in agricultural education is the Myers-Briggs Type Indicator (MBTI). The MBTI measures an individuals learning style as a function of their personality (Briggs & Myers, 1977). This instrument assesses a persons personality by identifying the preferences of a person in gathering information and making judgments. The four preferences are: Extroversion or Introversion (E or I), Sensing perception or Intuition perception (S or N), Thinking judgment or Feeling judgment (T or F), and Judgment or Perception (J or P). The preference of Sensing (S) and Intuition (N) addresses learning styles. The MBTI provides information about the ways learners prefer to perceive meaning (sensing vs. intuition), to express values and commitment (thinking vs. feeling), and to interact with the world (extroversion vs. introversion) (Rollins, 1988, 1990). Students with a Sensing (S) learning style need to move step-by step through new experiences with their senses as fully engaged as possible. This type of learner works best with established routines. They work steadily and patiently and are interested in facts and details. Students with an Intuition (N) learning style like global schemes with broad issues presented first. These students are likely to follow their inspirations and do not like routines (Briggs & Myers, 1977). Learning Styles Inventory (LSI) Kolb (1984) developed an instrument called the Learning Styles Inventory (LSI) based upon experiential learning theory. He describes four modes of learning. They are:

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38 Concrete Experience (feeling), Reflective Observation (watching), Abstract Conceptualization (thinking), and Active Experimentation (doing). Kolb (1984) states that an orientation toward concrete experience focuses on being involved in experiences and dealing with immediate human situations in a personal way. This type of learner uses an intuitive approach to solving problems. A learner oriented toward reflective observation focuses on understanding the meaning of ideas and situations. They emphasize understanding rather than practical application. This type of learner is good at looking at things from different perspectives and appreciating different points of view. Individuals with an orientation toward abstract conceptualization focus on using logic, ideas, and concepts. This learning style emphasizes thinking as opposed to feeling. This learner enjoys developing and following systematic plans. Learners oriented toward active experimentation focus on actively influencing people and changing situations. This learner emphasizes doing as opposed to observing. This type of learner is good at getting things done and enjoys accomplishment (Kolb, 1984). Research on Learning Styles Studies Involving High School Students Although there has been a significant amount of research regarding the effects of learning styles on achievement of post-secondary students in agricultural education, there has been relatively few dealing with secondary agricultural education students. The following is a discussion of the findings of those studies. Rollins (1990) identified the learning styles of 668 students in 18 high schools in Iowa using the Myers-Briggs Type Indicator (MBTI). The study found that the majority of students preferred the Sensing learning style. It was reported that individuals of this

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39 learning style prefer experiential and activity-oriented instruction. This supported the position of Briggs and Myers (1977) on this learning style. However, contrary to Briggs and Myers, this study found that those students with an Intuitive learning style also preferred learning in the same manner as those with the Sensing learning style. It was also reported that these findings were consistent for both males and females. Rollins and Scanlon (1991) examined the learning styles of 224 agricultural education students grades 9-12 in Pennsylvania. The researchers use the Learning Style Profile (LSP) developed by the National Association of Secondary School Principals to determine student learning style. The reported learning styles of the agricultural education students in this study were compared to a national sample of 5000 students of similar ages (Keefe & Monk, 1986). Rollins and Scanlon reported that their sample of students preferred more hands-on activities and small groups sizes than the national norm. In addition, the agricultural education students studied reported substantially less-developed skills in cognitive areas of analytical, spatial, discriminating, and sequential skills than the national norm. Dyer and Osborne (1996a) determined the learning styles of 258 students in 16 agricultural education classes in Illinois. This study utilized the GEFT to identify student learning style. In addition to the categories of field-dependent and field-independent identified by Witkin et al. (1971), Dyer (1995) identified a third category, field-neutral. This study found that students classified as field-neutral in their learning style by the GEFT instrument had higher achievement scores when taught using the problem solving approach instead of the subject matter approach to teaching.

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40 Using the same sample as the previous study, Dyer and Osborne (1999a) compared the retentive effectiveness of the problem solving approach to the subject matter approach. The problem solving approach was reported to be neither more nor less effective than the subject matter approach in producing higher short-term or long-term retention scores. No significant difference was found based on learning style on either short-term or long-term retention scores with either teaching method. Vicenti-Henio and Torres (1998) assessed the learning style of American Indian students using the GEFT. The sample included all Navajo students enrolled in the agricultural education program in a public high school located on a Navajo reservation which extends across the New Mexico and Arizona state line (n = 78). The researchers reported that the students tended to be field-independent (71%). Males tended to be field-independent as well (76%). However, females were evenly split between field-dependent (50%) and field-independent (50%). Garton, Spain, Lamberson, and Spiers (1999) described the relationships between students learning style, instructors teaching performance, and student achievement in an introductory animal science course. Using the GEFT, student learning styles were reported as 56% field-independent, 22% field-neutral, and 22% field-dependent. Student learning style was reported to have little to no influence on student achievement in the course or their perceptions of the instructors teaching performance. Studies Involving Post-Secondary Students Although a limited number of studies in agricultural education have measured the learning style of secondary students, the learning styles of post-secondary agricultural education students have been investigated in greater frequency. Raven, Cano, Garton, and Shelhamer (1993) described the learning styles of preservice agriculture education

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41 teachers at Montana State University (n = 18) and The Ohio State University (n = 25) using the Group Embedded Figures Test. They reported that the Montana State University students tended to be more field-independent and preferred a more student-centered approach to teaching than did their Ohio State counterparts. Additionally, there was no gender difference found in learning style preference. Both males and females tended to be field-independent. Cano and Garton (1994a) identified the learning style of preservice agriculture teachers with the Myers Briggs Type Indicator. The sample of this study included students enrolled in a methods of teaching course during the academic years of 1990, 1991, and 1992. The sample included 29 females and 53 males. It was reported that the highest percentage (23.2%) was ESTJ in their personality type. Cano and Garton stated that individuals of this type tend to be practical, realistic, matter-of-fact, and like to organize and run activities. The second most common profile was ISTJ (18.3%). This type of individual is serious, quiet, and logical. The third most common profile was ESFJ (13.4%). Individuals of this personality type are generally warm-hearted, talkative, and work best with encouragement and praise. These individuals main interest is in doing things that directly and visibly affect peoples lives. Using the same sample as the previous study, Cano and Garton (1994b) described the learning styles of the preservice agriculture teachers using the Group Embedded Figures Test. It was reported that the majority (58.5%) of the preservice teachers were field-independent in their learning style. This finding was consistent with both males (60.4%) and females (55.2%) reporting a field-independent learning style. It was reported that field-independent students earned higher scores on both microteaching

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42 exercises and overall course score than did students with a field-dependent learning style. Garton and Cano concluded that students with field-independent learning styles appeared to be more adapted at teaching utilizing the problem-solving approach. Marrison and Frick (1994) compared the extent to which academic and students perceptions of traditional lecture and computer multimedia instruction was influenced by learning style. This study used the Group Embedded Figures Test to indicate learning style. The population of this study was undergraduate students enrolled in an introductory agricultural economics course (n=75). It was reported that 43% of the students were classified as field-dependent and 57% were field-independent. It was further reported that learning style had no significant effect on achievement or overall perception of instruction between traditional lecture and computer multimedia instruction. Torres and Cano (1994) investigated the preferred learning style of students enrolled in the College of Agriculture at The Ohio State University. The study included a sample of 196 randomly selected senior students. Learning style was assessed using the Group Embedded Figures Test. It was reported that the students tended to be field-independent in learning style. Males preferred a field-independent style, however females were reported as preferring a field-dependent learning style. Additionally, differences in learning style preference were reported based on academic major. Students majoring in animal science, horticulture, agricultural education, food science, and dairy science tended to be field-independent. Students majoring in agricultural economics, agronomy, and agricultural communication tended to be field-dependent in their learning style.

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43 Whittington and Raven (1995) described the preferred learning style of student teachers in agricultural education at the University of Idaho and Montana State University. The population for this census study consisted of students majoring in agricultural education at those two institutions (n = 31). This study used the GEFT to assess learning style. It was reported that 74% of the student teachers were field-independent in their learning style. Most males (66.7%) and all females (100%) reported field-independent as their preferred learning style. This learning style preference trend held when student teachers were compared based on age classifications. Torres and Cano (1995) determined the learning styles of students enrolled in the College of Agriculture at The Ohio State University during the Autumn Quarter in 1992. A random sample of 196 students was selected from the population. Using the GEFT, Torres and Cano reported that 38.8% of the students were field-dependent and 61.2% were field-independent in their learning style. This study indicated that approximately 9% of the variance in critical thinking ability in students is uniquely accounted for by learning style. Cano (1999) described the learning styles and academic performance of 1994 incoming freshman students enrolled in the College of Food, Agricultural, and Environmental Sciences at The Ohio State University (n = 187). Cano reported that 56% of the of the incoming freshman were field-independent, while 44% were field-dependent. Based on student academic majors, Cano stated that students who are field-independent may be attracted to hard sciences, and field-dependent learners may be attracted to social sciences.

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44 Garton, Dyer, and King (2000) attempted to identify predictors of academic performance and retention of freshmen in the College of Agriculture, Food, and Natural Resources at the University of Missouri. The sample of this study consisted of an intact group of freshmen enrolled in a learning and development course (n = 245). It was reported that 56% of the students were field-independent in their learning style. Furthermore, 24% of the students were reported as field-neutral and 20% field-dependent. Garton, Dyer, and King reported that learners preferring a field-independent and field-neutral learning style exhibited greater academic performance, measured by GPA, than did field-dependent students. Rudd, Baker, and Hoover (2000) explored the relationship between learning style and student disposition toward critical thinking. The sample for this study consisted of students in four classes in the College of Agriculture and Life Sciences at the University of Florida (n = 174). The researchers reported that most students (67%) were field independent in their learning style. No significant difference in student learning style was reported based on gender. Additionally, it was reported that no correlations existed between critical thinking and learning style. Shih and Gamon (2002) investigated how students with different learning styles learned in web-based courses. This study included 99 students taking two non-major introductory biology courses. More than two thirds (69%) of the students were field-independent learners. It was reported that field-dependent students scored almost the same on the learning strategy scale as field-independent students. Socioeconomic Status Research on the effects of socioeconomic status, gender, and ethnicity has shown that it is difficult to discuss any one of these factors separately from the others when

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45 examining student achievement. Although socioeconomic status and/or ethnicity may appear to be meaningfully related to student achievement when examined individually (Fenwick, 1996; Wong & Alkins, 1999; Yellin & Koetting, 1991), this may be due to the fact that socioeconomic status and ethnicity are often coterminous (Abbott & Joireman, 2001). This means that students of some ethnic backgrounds also may be those who are unequally represented in lower socioeconomic groups. Webster, Young, & Fisher (1999) conduced a secondary analysis of the database known as the Third International Mathematics and Science Study (TIMSS). The TIMSS sampled students from three population groups in 45 countries. For their study, the researchers selected thirteen-year-old students from Australia, Canada, England, and the United States. For this study, socioeconomic status was determined by using the variables of mothers and fathers education, number of books in the home, and English speaking background. This study found that student gender and socioeconomic status accounted for a substantial degree of variance in student achievement. This study continued to state that most of that variance is explained at the student level, as opposed to the class or school level. In a study conducted by Abbott and Joireman (2001), which analyzed 1999 and 2000 school-level data obtained from the Washington State Office of the Superintendent of Public Instruction, it was found that 12 29% of the variance in achievement, depending on the grade level of the student and the achievement measure given, was uniquely explained by low socioeconomic status. It was also found that student ethnicity explained on average almost 33% of the variance in low socioeconomic status. Therefore, this study found that the relationship between ethnicity and academic

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46 achievement is mostly indirect. It found that ethnicity is correlated to low socioeconomic status, which in turn is related to academic achievement. In this study socioeconomic status was defined as the percentage of students in a given school who were on free and reduced lunch. Furthermore, ethnicity was defined as the percentage of White students in a school. Newsom-Stewart and Sutphin (1994) investigated tenth grade students perceptions of agriculture, environmental science and the relationship of academic and agricultural courses. The population of this study consisted of students in twelve schools and technical centers (n = 1,253) across the state of New York. Using a researcher designed instrument, the researchers reported that tenth grade students tended to have a positive view of the importance of the fields of agriculture and environmental science. No significant difference was reported between the perceptions based on gender or ethnic characteristics. Additionally, the students, regardless of ethnicity and gender, reported that they felt agriculture was most closely related to science followed by mathematics, communication, and computers. Hoffer, Rasinski, and Moore (1995) conducted an analysis of data collected in 1992 from the second follow-up survey of the National Education Longitudinal Study of 1988. The students included in this study were 8 th graders in 1988. Most of the students (85%) were high school seniors when this data was collected. The focus of this study was to examine students coursetaking patterns in high school and achievement in mathematics and science. One of the findings of this study was that there were no differences in the number of courses taken in mathematics or science based on gender. A difference was found between ethnic groups with Asians completing the most courses and Hispanic and

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47 Africa-American students completing the fewest. However, when examining the data based on socioeconomic status of the students families, the difference in number of courses taken between ethnic groups disappeared. Therefore, socioeconomic status was found to be a key factor influencing the number of science and mathematics courses taken in high school. Furthermore, the number of courses taken in each of the subject-matter areas was found to directly impact achievement in both areas. Guskey (1997) investigated the relationship between socioeconomic variables and school-level achievement results on the Kentucky Instructional Results Information System (KIRIS). Information was collected over a three year period from 49 schools within one school district. This study found that the correlations between percent of students in a school qualifying for free or reduced lunch benefits and percent of minority students were .82 for elementary schools, .92 for middle schools, and .96 for high schools. This study also found that the socioeconomic indicator of qualification for free or reduced lunch benefits explained much of the variation in level of achievement in a high-stakes, performance-based student assessment program. Lubienski (2001) examined the disparities between White and African-American students mathematical achievement. Data was drawn from the 1990 and 1996 National Assessment of Educational Progress (NAEP). The NAEP samples consist of several thousand 4 th 8 th and 12 th graders from both public and private schools. Socioeconomic status for this study was constructed using the variables of resources in the home (i.e. books, encyclopedia, newspapers) and parental education. No significant difference in NAEP scores was found between the achievement gains of male and female students. In examining difference in achievement scores across ethnicity, it was found that White

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48 students scored significantly higher than did African American students. Furthermore, when socioeconomic status and ethnicity were examined together a significant difference was found between both ethnic group and socioeconomic status. It was found that the lowest socioeconomic status White students scored equal to or higher than the highest socioeconomic status African American students. Presage Variables The presage variables described by Duncan and Biddle (1974) were controlled in this study through research design or statistical measures. An effort was made in the research design to provide similar student groups for each teaching method. The importance of this variable should not be seen as lacking. However, the focus of this study was on the other variables found in the model. Chapter Summary The purpose of this chapter was to describe the theoretical and conceptual frameworks, and delineate the empirical research pertinent to this study. Research literature regarding each of the variables to be studied was examined to gain an understanding of previous studies. In general, the findings regarding the effect of teaching approach on student content knowledge achievement are at best mixed. The subject matter approach was found to be commonly used as the control in studies that compared teaching approaches. Research in agricultural education is mixed as to the effect of learning style on student content knowledge achievement. Furthermore, studies that have described the learning style of students in agricultural education at both the secondary and post-secondary level are mixed as to learning style preference of students. Therefore, continued research is needed in this area.

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49

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CHAPTER 3 METHODS Chapter 1 described the rationale for evaluating the effects of investigative laboratory integration in secondary agricultural education courses. The primary purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill development across different learning styles. Chapter 2 described the theoretical and conceptual frameworks, and delineated the empirical research relevant to this study. Included in this chapter were reviews of literature and research pertaining to the following: context variables o learning style o gender o ethnicity process variables o subject matter approach o experiential learning o inquiry-based approach presage variables product variables o content knowledge achievement o science process skills In this chapter, methods used to address the research questions are discussed. This chapter reports the procedures, research design, population and sample, instrumentation, data collection procedures, and data analysis techniques. The independent variable in this study was the teaching method used in the agricultural education classes. Treatment groups utilized one of three levels of treatment: 50

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51 subject matter approach without laboratory experimentation, subject matter approach with prescriptive laboratory experimentation, subject matter approach with investigative laboratory experimentation. The dependent variables in this study were student content knowledge achievement and science process skill level. Characteristics that were treated as antecedent variables were student learning style, ethnicity, and gender. Covariates were used to adjust group means in order to compensate for previous knowledge in the subject matter. These covariate measures included pretests for the unit of instruction. Research Design This study utilized a quasi-experimental design. This design was selected due to the fact that random assignment of subjects to treatment groups was not possible. Therefore, intact groups were used. The study followed a variation of the nonequivalent control group design (Campbell & Stanley, 1963). In this study there was no group that received no treatment, as is the definition of a true control group as defined by Campbell and Stanley. However, Gall, Borg, and Gall (1996) stated that all groups may receive a treatment in the nonequivalent control group design. They state that the only essential features of this design are nonrandom assignment of subjects to groups and administration of a pretest and posttest to all groups. The variation of the nonequivalent control group design appears as follows: O 1 X 1 O 2 O 1 X 2 O 2 O 1 X 3 O 2 The first observation (O 1 ) consisted of a content knowledge pretest given to each participant to determine prior knowledge of the subject matter. Also, administered at this

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52 time were the Group Embedded Figures Test (GEFT) and the Test of Integrated Process Skills (TIPS). All activities included in the first observation (O 1 ) were conducted approximately one week prior to the beginning of instruction in the selected unit. At the initial visit to each school, student demographic data were requested from the school student services department. Student confidentiality was maintained throughout this process by assigning each student an identification number. All records were sent to the researcher with this identification number and not student names. One of three treatments was utilized with each group. There were two experimental treatments (X 1 and X 2 ). Each treatment lasted 4 6 weeks. The first experimental treatment (X 1 ) consisted of the subject matter approach with prescriptive laboratory experimentation activities. The second experimental treatment (X 2 ) consisted of the subject matter approach with investigative laboratory experimentation. The contrasting treatment (X 3 ) was the subject matter approach without laboratory experimentation. The second observation (O 2 ) occurred directly following the treatment. It consisted of a content knowledge achievement posttest for the unit of instruction and the Test of Integrated Process Skill II, a parallel version of the science process skill instrument administered during the first observation (O 1 ). The basic threats to internal validity identified by Campbell and Stanley (1963) include history, maturation, testing, instrumentation, regression, subject selection, mortality, and interaction effects. The nonequivalent control group research design controls all of the threats except regression and interaction. The risk of regression, however a concern whenever a pretest-posttest procedure is used to determine the amount

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53 of change as result of a treatment, can be minimized if subjects are not selected based on extreme scores (Campbell & Stanley, 1963). Therefore, since none of the groups were selected via extreme scores of any kind, regression effects should not be a serious threat to internal validity in this study. Gall, Borg, and Gall (1996) state that the main threat posed by interaction in this type of research design is the possibility that differences found in posttests are due to preexisting group differences, rather than to treatment effects. Therefore to address the threat of interaction to internal validity, several steps were taken. The use of multiple classroom settings helped to reduce the risk of interaction. Also, using the covariates of content knowledge achievement pretest and science process skill pretest scores to statistically adjust the means on the posttest addressed this concern. In conducting a study of this kind, factors in addition to those affecting internal validity must be controlled. The factor of individual teaching ability of the teachers involved in the study was addressed by the use of a number of different teachers within each treatment. Additionally, the content selected to be delivered in the treatments was deemed appropriate by a panel of experts to be delivered via all of the teaching methods included in the study. All teachers involved in the study participated in professional development activities to instruct them on how to properly deliver each treatment as recommended by Boone (1988). These professional development activities were conducted by the researchers and ranged from one to two hours in length. In addition to individual instruction on the teaching method, each teacher involved in the study received a researcher developed videotape containing further instruction on the teaching method and general information about the study.

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54 The unit of instruction on plant germination was selected from the Agriscience Foundations I curriculum published by the Florida Department of Education. The three treatments were randomly assigned to the classes. To ensure proper utilization and adherence to the assigned treatment, each teacher presentation was audio taped and analyzed by the researcher. An additional threat to internal validity was posed by the selection of participants for the study. This included the teachers, classes, and students involved in this study. The sample was selected based upon the ability of the teacher to effectively deliver all three of the teaching approach treatments. Whereas treatments were randomly assigned to classes, data were collected on individual students. This threat to internal validity, however much a concern, is unavoidable as random selection and assignment of participants was not possible in the high school setting. Procedures Following the suggestion made by Boone (1988) for conducting teaching method studies using teachers to deliver the treatment, precautions were taken to ensure teacher conformity to the assigned teaching approach. Prior to beginning the study, teachers were provided professional development on their assigned teaching method. All materials needed by the teacher to deliver the treatment (lesson plans, handouts, assessment instruments, etc.) were provided by the researcher. As mentioned previously, the teachers audio recorded each lesson. At the conclusion of the treatment, the researcher analyzed the audio recordings to determine the level to which the treatment was administered. The researcher designed Treatment Delivery Analysis Scoresheets (Appendix A) were used. Following procedures similar to those of Dyer (1995), the first class period and two other randomly selected classes were

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55 evaluated. Tapes were scored on a 10-point scale based upon the teachers adherence to the assigned teaching approach. It was determined a priori that a mean of greater than 6.0 would be necessary to accurately reflect the respective teaching approach. It was determined a priori that students in classes in which the assigned teaching approach had not been properly utilized as determined by the Treatment Delivery Analysis Scoresheet, would be removed from the sample. Approximately one week prior to instruction, students completed the activities included in the first observation of the research design. This included three assessments. The first of which was a content knowledge pretest to determine their entry level of knowledge. The Group Embedded Figures Test (GEFT) was administered to measure student learning styles. The Test of Integrated Process Skills (TIPS) was used to measure the students entry level of science process skill. It was determined a priori that in order to be deemed to have received the treatment, a student must be in attendance at least 80 percent of the days in which the treatment was being delivered. Students not meeting this requirement were removed from the study. Following the instruction, students were administered the content knowledge achievement posttest and the Test of Integrated Process Skill II, a parallel version of the science process skill instrument administered during the first observation. At the conclusion of all testing, students and teachers were debriefed concerning their participation in the study. Population The population for this study was Florida students enrolled in an introductory agriscience course. A purposive sample was selected based upon the ability of the teacher to effectively deliver all three of the teaching approach treatments. All teachers

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56 included in this study were identified as high quality teachers by the agricultural education faculty at the University of Florida. This designation was made based upon teaching observations made by faculty. In addition, these teachers have served as supervisors to agricultural education student teaching interns. Each teacher was randomly assigned a treatment (teaching method) group. Sample Size The formula suggested by Hays (1973) was used to determine the size of the sample in order to ensure the ability to properly measure the variables of the study, yet avoid finding significance because of inflated sample size. A sample size was selected as to limit the probability of committing a Type I error to .05, achieve a desired power of .90, and to be able to detect variances greater than .10 in the dependent variables due to the independent variable. The following formula was used to determine sample size n = 2 [Z (1-/2) Z where Z (1-/2) equals the z score for the alpha level desired (.05), Z equals the z score for the desired power (.90), and equals the effect size in standard deviation units. is computed using the formula = 2(w 2 ) / (1 w 2 ) where w 2 represents the amount of variance of the dependent variable accounted for by the independent variable. The calculations for this study, using the above formulas are = 2 [.10/(1-.10)] = .66 n = 2[1.96 (-1.64)] 2 / .66 2 = 59.5 It was determined, using this formula that a minimum of 60 students in each treatment were required to achieve the appropriate sample size. Based on the findings of Flowers

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57 (1986), Boone (1988), and Dyer (1995), this type of study experiences a mortality rate of approximately 50%. Therefore, this number was doubled for each treatment in order to offset effects of mortality. Instrumentation The researcher developed the instrument used to collect data for the dependent variable of content knowledge achievement. The Test of Integrated Process Skills (Dillashaw & Okey, 1980) was used to measure science process skill. The Group Embedded Figures Test (Witkin, Oltman, Raskin, & Karp, 1971) was used to measure the antecedent variable of learning styles. Data concerning the antecedent variables of ethnicity, gender, and other student characteristics were reported to the researcher by the schools student services department from student records. Lesson plans for the unit of instruction were created by the researcher to serve as parameters for the treatments. Unit of Instruction Plans Instructional plans appropriate to the teaching methods used were developed using information from Biological Science Applications in Agriculture (Osborne, 1994). The content of the unit was designed to address the plant science portion of Florida Student Performance Standard 06.0 for the Agriscience Foundations I course (Florida Department of Education, 2002). The lessons within this unit were designed to take five to six weeks to complete. The plant science subject matter to be taught was consistent among all three sets of instructional plans. All students in the introductory agriscience classes included in the study were taught all lessons within the unit of instruction. However, approximately one-third of the students received the instruction utilizing the subject matter approach with prescriptive laboratory experimentation activities, one-third received the instruction utilizing the subject matter approach with investigative laboratory experimentation, and

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58 one-third received the instruction using the subject matter approach without laboratory experimentation. The instructional plans (Appendix B) were evaluated for content validity by a panel of experts from the Agricultural Education and Communication Department at the Univeristy of Florida and local high schools. Content Knowledge Achievement Assessment Instruments In order to measure student prior content knowledge and content knowledge achievement, the researcher designed a content knowledge pretest (Appendix C) and a content knowledge achievement posttest (Appendix D). All tests were similar in design and difficulty. Teaching objectives were used as a guide in constructing these parallel assessment instruments. A panel of experts from the Agricultural Education and Communication Department at the University of Florida and local high schools was used to determine face and content validity of the instruments. Assessment instruments were evaluated by the panel of experts to verify that each objective included in the lesson plans were properly addressed in the instrument. Learning Styles Inventory The Group Embedded Figures Test (GEFT) (Witkin et al., 1971) was used to assess student learning style. The validity of this instrument was established by Witken et al. In addition, a Spearman-Brown reliability coefficient of .82 was reported by the developers of the instrument. Science Process Skill Assessment Instrument Like the Group Embedded Figures Test, the Test of Integrated Process Skills (TIPS) is considered a standardized test. The TIPS was designed to assess proficiency in the science process skills associated with planning, conducting, and interpreting results from investigations (Dillashaw & Okey, 1980). Dillashaw and Okey stated that this

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59 instrument is a valid and reliable measure of process skill achievement for students in the 7 th to 12 th grades. Reliability of the test was found using Cronbachs alpha to be .89. The mean item discrimination of the instrument was reported as .40. In addition the developers of this instrument reported a readability index of 9.2 for this instrument. Treatment Delivery Analysis Scoresheet To ensure that teachers involved in this study were following the correct teaching approach, teachers were asked to audiotape each class period in which the treatment was being administered. An instrument was developed by the researcher to be used in analyzing those tapes (Appendix A). A panel of experts consisting of the agriculture teacher education faculty of the Agricultural Education and Communication Department at the University of Florida evaluated the instrument for content validity. Analysis of Data Data were analyzed using the SPSS version 12.0 for Windows software package. Analysis of the first objective involved descriptive statistics and included frequencies, means, and standard deviations. The second two objectives were examined using backward regression analyses. All hypotheses were tested using multivariate analysis of covariance (MANCOVA). Univariate analysis of covariance (ANCOVA) was used as a follow-up procedure, when appropriate. Agresti and Finlay (1997) stated that these procedures are appropriate when analyzing two or more dependent variables (content knowledge achievement and science process skill) while statistically controlling one or more variables (teaching approach, learning style, student demographic data). These procedures also allow the researcher to control the overall alpha level and decrease the chance of committing a Type I error.

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60 Chapter Summary In this chapter, the methods used to address the research questions were discussed. This chapter reported the procedures, research design, population and sample, instrumentation, data collection procedures, and analysis of data. The independent variable in this study was reported as the teaching method used in the agricultural education classes. The treatments investigated in this study were identified as: subject matter approach without laboratory experimentation, subject matter approach with prescriptive laboratory experimentation, and subject matter approach with investigative laboratory experimentation. The dependent variables in this study were identified as student content knowledge achievement and science process skill level. Characteristics which were treated as antecedent variables were student learning style, ethnicity, and gender. It was reported that covariates were used to adjust group means in order to compensate for previous knowledge in the subject matter and the individual learning ability of the students. These covariate measures included pretests for the unit of instruction. It was reported in this chapter that the design of this study was a quasi-experimental design referred to as nonequivalent control group design by Campbell and Stanley (1963). Threats to validity in this study were discussed. Data collected were identified as pretest content knowledge scores, content knowledge achievement scores, preand posttreatment science process skill scores (as measured by the TIPS instrument), student learning styles (as measured by the GEFT instrument), student attendance records, and audiotapes of classes. Method of data analysis used were noted as multivariate analysis of covariance, univariate analysis of

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61 covariance, means, standard deviations, correlations, frequencies, percentages, and post hoc analyses.

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CHAPTER 4 RESULTS AND DISCUSSION Chapter 1 described the rationale for evaluating the effects of investigative laboratory integration in secondary agricultural education courses. The primary purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill achievement across learning styles, gender, and ethnicity. Chapter 2 described the theoretical and conceptual frameworks and delimited the empirical research relevant to this study. The study was framed around Mitzels theory that the outcome of learning (product) is influenced by the context variables that students contribute to the educational process, the presage variables contributed by the teacher, and the process variables contributed by the learning environment. Included in this chapter were reviews of literature and research pertaining to the following: context variables o learning style o gender o ethnicity process variables o subject matter approach o experiential learning o inquiry-based approach presage variables product variables o achievement o science process skills 62

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63 In Chapter 3 the methods used to address the research questions were discussed. This chapter reported the procedures, research design, population and sample, instrumentation, data collection procedures, and analysis of data. The independent variable in this study was the teaching method used in the agricultural education classes. Treatment groups utilized one of three levels of treatment: subject matter approach without laboratory experimentation, subject matter approach with prescriptive laboratory experimentation, subject matter approach with investigative laboratory experimentation. The dependent variables in this study were student content knowledge achievement and science process skill level. Characteristics that were treated as antecedent variables were student learning style, ethnicity, and gender. Covariates were used to adjust group means in order to compensate for previous knowledge in the subject matter. These covariate measures included pretests for the unit of instruction. It was reported in Chapter 3 that the design of this study was a quasi-experimental design referred to as nonequivalent control group design by Campbell and Stanley (1963). Threats to validity in this study were discussed. Data to be collected were pretest scores, content knowledge achievement scores, science process skill scores (as measured by the TIPS instrument), student learning styles (as measured by the GEFT instrument), student attendance records, and audio tapes of classes. Data were analyzed using a multivariate analysis of covariance, univariate analysis of covariance, means, standard deviations, correlations, frequencies, percentages, and post hoc analyses.

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64 This chapter presents the findings obtained by this study. The results address the objectives and hypothesis of the study in determining the influence of learning styles, gender, and ethnicity on content knowledge achievement and science process skill ability. The purposive sample used in this study consisted of students enrolled in introductory agriscience courses in Florida. A total of ten different schools across Florida were selected to participate in this study. A total of 501 students were enrolled in classes in the selected schools from which data were collected (see Table 4-1). Table 4-1 Study Treatment Group Membership Totals Treatment Group # of Schools # of Students Subject Matter Only 3 168 Prescriptive Laboratory 3 151 Investigative Laboratory 4 182 Total 10 501 No data were received from one participating school in the subject matter group. Repeated contacts were made with the participating teacher, however, since no data were obtained, the students in this class were removed from the study. Likewise, one of the participating teachers in the investigative laboratory group left teaching during the study treatment. Therefore, students in this class were also removed from the study. Additionally, one teacher in the investigative group was determined to not have fully delivered the treatment. This determination was made by the researcher using the Treatment Delivery Analysis Scoresheet to review the audiotapes submitted by the participating teacher. Since it was determined that the treatment was not adequately administered, the students in this class were likewise removed from the study. This mortality resulted in the sample size being reduced to 352 students. This equates to a

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65 29.7% mortality rate for this study. Previous experimental studies using intact classes reported similar or higher mortality rates. As outlined in Chapter 3, data were collected at various points throughout the treatment. Content knowledge was assessed both prior to, and following, the treatment. The response rate for each collection was 70.7% and 62.5%, respectively (see Table 4-2). Likewise, the science process skill ability of the participants was measured using the Test of Integrated Process Skills [TIPS] (Dillashaw & Okey, 1980) preand post-treatment. The response rates for preand post-test TIPS administration were 79.8% and 50.9%, respectively. Learning style data were collected with a response rate of 81.0%. Table 4-2 Response Rates for Data Collection Components (n = 352) Data Collection Component n Response Rate Content Knowledge Pretest 249 70.7% Content Knowledge Posttest 220 62.5% Science Process Skills Pretest 281 79.8% Science Process Skills Posttest 179 50.9% Learning Styles Instrument 285 81.0% Prior to data analysis, post hoc reliability was established for each data collection instrument used in the study. All instruments consisted of data with items measured as right or wrong. Therefore, the instruments were analyzed for reliability using the Kuder-Richardson 20 formula (Gall, Borg, & Gall, 1996). Posttest instruments for both the content knowledge achievement and science process skill were parallel forms to the pretest instruments. A reliability coefficient of .92 was determined for the content knowledge achievement instruments (see Table 4-3). Analysis of reliability of the science process skill instrument yielded a coefficient of .72.

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66 Table 4-3 Post-Hoc Instrument Reliability Instrument Reliability Content Knowledge Achievement .92 Science Process Skill .72 The length of time needed for teachers to deliver the instruction that was part of this study varied between groups (see table 4-4). The average number of minutes of instruction across all groups was 1542. The teachers in the subject matter only and prescriptive laboratory groups averaged 1410 and 1392 minutes of instruction, respectively. The longest reported time spent on activities included in this study was reported by the investigative laboratory group (M = 1900). Table 4-4 Average Length of Treatment Treatment Group # of Schools Mean Minutes of Instruction Subject Matter Only 2 1410.0 Prescriptive Laboratory 3 1391.7 Investigative Laboratory 2 1900.0 Total 7 1542.1 Objective One: Describe the Learning Styles, Ethnicity, and Other Demographic Characteristics of Participants in this Study. Grade Level Of the 322 participants that reported grade level data, 62.7% (n = 202) were in the ninth grade (see Table 4-5). The remainder of the participants were in either the tenth grade (n = 64, 19.9%), eleventh grade (n = 39, 12.1%), or twelfth grade (n = 17, 5.3%). The grade level breakdown by treatment groups varied from that of the overall sample (see Figure 4-1). Almost 80% of the students in the investigative laboratory group were in the ninth grade as compared to only 49% in the prescriptive laboratory group. Therefore, results should be interpreted with caution in regards to grade level.

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67 Table 4-5 Participant Grade Level (n= 322) Treatment Group SM PL IL Total Grade Level n % n % n % n % Ninth 47 62.7 66 48.9 89 79.5 202 62.7 Tenth 19 25.3 37 27.4 8 7.1 64 19.9 Eleventh 9 12.0 22 16.3 8 7.1 39 12.1 Twelfth 0 0.0 10 7.4 7 6.3 17 5.3 Note. SM = Subject Matter Group; PL = Prescriptive Laboratory Group; IL = Investigative Laboratory Group 9101112Grade Level 020406080100 Treatment GroupSMPLIL Frequency Figure 4-1 Distribution of Participant Grade Level Ethnicity Participant ethnicity was categorized into the groups of Black, White, non-Hispanic, Hispanic, and Other. The majority of students participating in this study categorized themselves as White (56.0%). The second largest group was Hispanic (34.5%) followed by Black (7.9%) and Other (1.6%). The ethnic make-up of each of the treatment groups varied from that of the entire sample (see Table 4-6). Approximately 47% of the students in the subject matter group were Hispanic as compared to only 23%

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68 in the investigative laboratory group. Therefore, results should be interpreted with caution in regards to ethnicity. Table 4-6 Participant Ethnicity (n = 316) Treatment Group SM PL IL Total Ethnicity n % n % n % n % Black 5 6.8 12 9.0 8 7.4 25 7.9 White, non-Hispanic 33 44.6 71 53.0 73 67.6 177 56.0 Hispanic 35 47.3 49 36.6 25 23.1 109 34.5 Other 1 1.4 2 1.5 2 1.9 5 1.6 Note. SM = Subject Matter Group; PL = Prescriptive Laboratory Group; IL = Investigative Laboratory Group Gender The majority of participants in this study (66.5%) was male. Treatment groups closely followed the same gender makeup as did the entire sample (see Table 4-7). Table 4-7 Participant Gender Distribution (n = 322) Treatment Group SM PL IL Total Gender n % n % n % n % Male 55 73.3 87 64.9 72 63.7 214 66.5 Female 20 26.7 47 35.1 41 36.3 110 33.5 Note. SM = Subject Matter Group; PL = Prescriptive Laboratory Group; IL = Investigative Laboratory Group Learning Style The Group Embedded Figures Test (GEFT) (Witkin et al., 1971) was used to assess student learning style. According to the authors of the GEFT, individuals may be classified as either field-dependent or field-independent based upon their score on this instrument. Possible scores range from 0 to 18, with the national grand mean being reported by Witkin et al. as 11.3. Those individuals with scores below this average are considered field-dependent. Individuals with scores above 11.3 are considered field

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69 independent. However, Garton and Raven (1994) reported a third category of learners. These learners score toward the center of this bipolar scale. Dyer (1995) suggested that for high school students the following scale (Figure 4-2) should be used to categorize student learning styles. Abstract Concrete 0 8 9 11 12 18 Field-Dependent Field-Neutral Field-Independent Figure 4-2 GEFT Score Interpretation Guidelines The mean GEFT score for respondents in this study was 7.6 (SD = 4.74). Figure 4-3 shows the distribution of GEFT scores. 051015GEFT Score 0510152025 Frequency Figure 4-3 GEFT Score Distribution A majority (60.7%) of students was categorized as field-dependent. The next largest group was field-independent learners (23.2%), followed by field-neutral learners

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70 (16.1%) (see Table 4-8). The learning style makeup of each of the treatment groups was similar to that of the entire sample (see Figure 4-4). Table 4-8 Participant Learning Style Distribution by Treatment Group (n = 285) Treatment Group SM PL IL Total Learning Style n % n % n % n % Field-Dependent 42 59.2 73 60.3 58 62.4 173 60.7 Field-Neutral 13 18.3 18 14.9 15 16.1 46 16.1 Field-Independent 16 22.5 30 24.8 20 21.5 66 23.2 Note. SM = Subject Matter Group; PL = Prescriptive Laboratory Group; IL = Investigative Laboratory Group FDFNFILearnin g St y le 020406080 Treatment GroupSMPLIL Frequency Figure 4-4 Learning Styles by Treatment Group An exploration of learning styles by grade level revealed that the majority of students in all grade levels were field-dependent in their learning style (see Table 4-9). The percentage of field-neutral and field-independent learners increased for eleventh and twelfth grade students. With the exception that approximately 24% of the students in the eleventh grade were field-neutral as compared to no students having a field-neutral

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71 learning style in the twelfth grade. Therefore, results should be interpreted with caution in regards to learning style across grade level. Table 4-9 Participant Learning Style Distribution by Grade level (n = 284) Grade Level 9 10 11 12 Learning Style n % n % n % n % Field-Dependent 114 62.0 32 60.4 18 54.5 8 57.1 Field-Neutral 30 16.3 8 15.1 8 24.2 0 0.0 Field-Independent 40 21.7 13 24.5 7 21.2 6 42.9 An analysis of learning styles based upon student gender is shown in Table 4-10. The majority of both male (58.8%) and female (63.5%) students were field-dependent in their learning style. Approximately the same percentage of males and females were also categorized as field-neutral (17.6% and 13.5%, respectively) and field-independent (23.5% and 22.9%, respectively). Table 4-10 Participant Learning Style Distribution by Gender (n = 283) Gender Male Female Learning Style n % n % Field-Dependent 110 58.8 61 63.5 Field-Neutral 33 17.6 13 13.5 Field-Independent 44 23.5 22 22.9 Content Knowledge Achievement Each students content knowledge achievement was determined using the researcher developed content knowledge achievement pretest and posttest instruments. The maximum possible score on these parallel instruments was 50. Pretest data were collected from 249 participants with an overall mean of 16.39 (SD = 5.04) (see Figure 4-5). The mean pretest scores by treatment group are shown in Table 4-11. The subject matter group reported the highest pretest mean (M = 18.09, SD = 5.07). The prescriptive

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72 laboratory group and the investigative laboratory group had similar mean content knowledge pretest scores (M = 15.98, SD = 4.93; M = 15.47, SD = 4.86; respectively). Posttest data were collected from 220 students. The overall mean of the content knowledge achievement posttest was 20.59 (SD = 6.79) (see Figure 4-6). The highest posttest score mean recorded was the subject matter group. This group had a mean of 24.63 (SD = 5.93). The posttest means for the prescriptive laboratory group and the investigative laboratory group were 18.30 (SD = 6.00) and 20.53 (SD = 7.16) respectively (see Table 4-11). Table 4-11 Instrument Scores by Treatment Group Treatment Group SM PL IL Total Instrument M SD M SD M SD M SD Content Knowledge Pretest 18.09 5.07 15.98 4.93 15.47 4.86 16.39 5.04 Content Knowledge Posttest 24.63 5.93 18.30 6.00 20.53 7.16 20.59 6.79 Science Process Skills Pretest 16.17 5.38 16.39 5.58 14.01 5.73 15.57 5.66 Science Process Skills Posttest 18.62 6.17 14.34 6.66 15.59 6.07 15.81 6.66 Content Knowledge Gain Score a 6.27 4.84 1.72 6.36 5.04 5.89 3.93 6.15 Science Process Skill Gain Score a 2.02 5.19 -2.50 6.20 3.20 5.80 -0.17 6.33 Note. SM = Subject Matter; PL = Prescriptive Laboratory; IL = Investigative Laboratory a Gain score = Posttest score minus pretest score The content knowledge gain score was calculated by subtracting the pretest score from the posttest score. The overall mean content knowledge gain score as reported in Table 4-11 was 3.93 (SD = 6.15). The largest content knowledge skill gain score was reported for the subject matter group of 6.27 (SD = 4.84). The investigative laboratory group had a mean content knowledge skill gain score of 5.04 (SD = 5.89). The

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73 prescriptive laboratory group reported a gain score of 1.72 (SD = 6.36). A distribution of content knowledge skill gain scores may be found in Figure 4-7. 102030Pretest Score 0102030405060 Frequency Figure 4-5 Distribution of Participant Content Knowledge Achievement Pretest Scores 010203040Posttest Score 051015202530Frequency Figure 4-6 Distribution of Participant Content Achievement Posttest Scores

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74 Science Process Skill The Test of Integrated Process Skills was used to determine the science process skill level of students both prior to (pretest) and following (posttest) the treatment. The overall mean of the pretest was 15.57 (SD = 5.66) of a possible 36 (see Table 4-11). The mean pretest science process skill scores were similar between the subject matter (M = 16.17, SD = 5.38) and prescriptive laboratory groups (M = 16.39, SD = 5.58). The mean pretest score for the investigative group was slightly lower at 14.01 (SD = 5.73). A distribution of science process skill pretest scores may be found in Figure 4-8. -100.1020Content Gain Score 010203040 Frequency Figure 4-7 Distribution of Participant Content Knowledge Gain Scores The overall mean for the science process skills posttest was 15.84 (SD = 6.66). The highest posttest score mean of 18.62 (SD = 6.17) was recorded for the subject matter group. The prescriptive laboratory and investigative laboratory groups reported means of 14.34 (SD = 6.66) and 15.59 (SD = 6.07) respectively (see Table 4-11). A distribution of science process skill posttest scores may be found in Figure 4-9.

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75 The science process skill gain score was calculated by subtracting the pretest score from the posttest score. The overall mean science process skill gain score, as reported in Table 4-11, was -0.17 (SD = 6.33). The largest science process skill gain score was reported for the investigative laboratory group of 3.20 (SD = 5.80). The subject matter group had a mean science process skill gain score of 2.02 (SD = 5.19). The prescriptive laboratory group reported a gain score of -2.50 (SD = 6.20). A distribution of science process skill gain scores may be found in Figure 4-10. 51015202530Pretest Score 051015202530 Frequency Figure 4-8 Distribution of Participant Science Process Skill Pretest Scores

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76 5101520253035Posttest Score 0102030 Frequency Figure 4-9 Distribution of Participant Science Process Skill Posttest Scores -20-10010TIPS Gain Score 010203040 Frequency Figure 4-10 Distribution of Participant Science Process Skill Gain Scores

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77 Relationships Between Variables Prior to any inferential analysis of the data, all variables were examined for correlations. For the purpose of discussion, the terminology proposed by Miller (1994) was used to indicate the magnitude of the correlations. According to Miller, correlations between .01 and .09 are considered negligible, .10 to .29 are low, .30 to .49 are moderate, .50 to .69 are substantial, .70 to .99 are very high, and a correlation of 1.00 is a perfect correlation. Pearson Product Moment correlations were used to determine the relationships between the variables (see Table 4-12). As would be expected, very high correlation was found between content knowledge posttest score and content knowledge gain score (r = .70). Substantial correlations were discovered between content knowledge posttest score, content knowledge pretest score (r = .50), and science process skill posttest (r = .55). A substantial correlation was also found between science process skill posttest score and science process skill gain score (r = .65). A moderate correlation was discovered between content knowledge posttest score and science process skill pretest score (r = .46). Moderate correlations were also discovered between content knowledge pretest score and science process skill pretest score (r = .48) and science process skill posttest score (r = .43). Moderate correlations were also discovered between science process skill pretest score and content knowledge posttest (r = .44), science process skill posttest score (r = .47), science process gain score (r = -.36), and GEFT score (r = .42). Additionally, moderate correlations were discovered between GEFT score and science process skill posttest score (r = .38). Several variables with low correlations were observed.

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Table 4-12 Correlations Between Variables 78 Variable 1 2 3 4 5 6 7 1. Content Pretest -.504 -.258 .479 .431 .062 .260 2. Content Posttest --.704 .441 .552 .248 .292 3. Content Gain Score -.106 .289 .231 .089 4. Science Process Pretest -.474 -.356 .420 5. Science Process Posttest -.654 .377 6. Science Process Gain Score -.031 7. GEFT Score

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79 Objective Two: Describe the Variance in Content Knowledge Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics. To address this objective, backwards-stepwise regression was selected as the means by which to determine the best model for predicting content knowledge gain score. Variables were removed from the model if that variables F-value did not have a probability equal to or less than .05. The backward regression procedure was selected due to the fact that it utilizes all available variables to build a model that consists of only variables that contribute significantly to predicting the dependent variable (Agresti & Finlay, 1997). Variables first included in the backward regression model were ethnicity, gender, learning style, grade level, treatment group, content knowledge pretest, and science process skill pretest. The following categorical variables were entered using dummy codes: Learning Style: 1 = field-dependent; 0 = field-independent Gender: 1 = male; 0 = female Ethnicity: 1 = white, non-Hispanic; 0 = minority Grade Level: o 9 th grade: 1 = yes; 0 = no o 10 th grade: 1 = yes; 0 = no o 11 th grade: 1 = yes; 0 = no Treatment Group: o Subject matter: 1 = yes; 0 = no o Prescriptive laboratory: 1 = yes; 0 = no A model consisting of content knowledge pretest, science process skill pretest, ethnicity, treatment group, and learning style was identified as being the best model to predict content knowledge gain score, F( 190 ) = 16.71, p <.001. R 2 for the model was .35; adjusted R 2 was .33. Table 4-13 shows the regression coefficients for this model. Field-dependent learning style (t = -2.35, p = .02), subject matter treatment group (t = 2.40, p = .02), prescriptive laboratory treatment group (t = -3.86, p <.001), ethnicity (t = 2.27, p =

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80 .02), science process skill pretest score (t = 5.07, p <.001), and content knowledge pretest score (t = -7.77, p <.001) contributed significantly ( = .05) to predicting content knowledge gain score. These variables accounted for 33% of the variance in content knowledge gain scores. Table 4-13 Backward Regression Analysis to Predict Content Knowledge Gain Scores Variable B SE t p Constant 9.42 2.04 4.62 <.001 Learning Style a -2.25 .96 -.15 -2.35 .02 Treatment Group Subject Matter b 2.45 1.02 .18 2.34 .02 Prescriptive Laboratory b -3.63 .94 -.29 -3.86 <.001 Ethnicity c 2.14 .94 .14 2.27 .02 Science Process Skill Pretest .41 .08 .35 5.07 <.001 Content Knowledge Pretest -.67 .09 -.54 -7.77 <.001 Note. F( 190 ) = 16.71, p <.001; R 2 = .35; Adjusted R 2 = .33 a Coded as 1 = field-dependent; 0 = field-independent b Coded as 1 = member of group; 0 = not a member of group c Coded as 1 = white, non-Hispanic; 0 = minority Objective Three: Describe the Variance in Science Process Skill Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics. A procedure similar to that which was used to address objective two was utilized to address this objective. Backwards-stepwise regression was used to select the best model for predicting science process skill gain score using learning styles, ethnicity, and other demographic characteristics. Variables that were categorical in nature were coded in the same manner as was done in objective two of this study. A model including the variables of learning style, treatment group, gender, science process pretest, and content knowledge pretest was found to be the most predictive. This linear combination of variables significantly predicted science process skill gain scores, F( 157 ) = 18.39, p <.001. R 2 for the model was .38, adjusted R 2 was .36. Table 4-14 shows the regression coefficients for this model. Field-dependent learning style (t = -3.01, p = .003), prescriptive laboratory

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81 group membership (t = -5.30, p <.001), gender (t = -2.52, p = .01), science process skill pretest score (t = -6.51, p <.001), and content knowledge pretest score (t = 2.38, p =.02) contributed significantly ( = .05) to predicting science process skill gain score. These four variables accounted for 36% of the variance in science process skill gain scores. Table 4-14 Backward Regression Analysis to Predict Science Process Skill Gain Scores Variable B SE t p Constant 11.20 2.34 5.00 <.001 Learning Style a -3.11 1.03 -.21 -3.01 .003 Treatment Group Prescriptive Laboratory b -4.42 .83 -.35 -5.30 <.001 Science Process Skill Pretest -.58 .09 -.49 -6.51 <.001 Content Knowledge Pretest .22 .09 .18 2.38 .02 Gender c -2.18 .87 -.16 -2.52 .01 Note: F( 157 ) = 18.39, p <.001; R 2 = .38; Adjusted R 2 = .36 a Coded as 1 = field-dependent; 0 = field-independent b Coded as 1 = member of group; 0 = not a member of group c Coded as 1 = male; 0 = female Hypothesis Tests The dependent variables in this study were content knowledge gain and science process skill gain. Both of these variables were interval data. The independent variables in this study were learning style, grade level, ethnicity, gender, and treatment group. All independent variables were categorical data. Covariates in this study were content knowledge pretest scores and science process skill pretest scores. Covariates were interval in nature. Tests of Assumptions of Multivariate Analysis of Covariance The goal of this study was to examine the effect on the dependent variables (content knowledge gain and science process skill gain) by the independent variables (learning style, grade level, ethnicity, gender, and treatment group). Therefore, the multivariate analysis of covariance (MANCOVA) procedure was used to analyze data.

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82 This procedure is appropriate when determining the differences between categorical independent variables on multiple interval dependent variables while statistically controlling for other variables (Stevens, 1992). For a single dependent variable, the assumptions for proper application of an analysis of variance procedure require that the groups must be random samples from normal populations with the same variance. Since the MANCOVA procedure is similar in nature to the single variable analysis of variance, these assumptions are extended to this procedure as well. The assumptions of the MANCOVA procedure are the dependent variables have a multivariate normal distribution with an equal variance-covariance matrix in each group (Kirk, 1982). Furthermore, since covariate measures were used, the assumption of homogeneity of regression for the covariate measures must also be met. Normality As a quasi-experimental design using intact groups, random sampling of subjects was not possible. Therefore, experimental control of this assumption was not practical, and a possible violation of the normality assumption occurred. However, as suggested by Kirk (1982), some degree of randomization was accomplished through the random assignment of treatment to the intact groups, minimizing this threat. Homoscedasticity Homoscedasticity, or homogeneity of variance, was assessed by using Boxs M procedure. This statistic follows the F distribution. A statistically significant F value indicates that the homoscedasticity assumption is not met. The Boxs M statistic for this study was 76.63, with a value of F (48, 2030) = 1.18, p = .19. Since the Boxs M test statistic was not significant = .05), the assumption of homoscedasticity was met.

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83 Multivariate Test of Effects A multiple analysis of covariance procedure was used to determine if significant differences existed between groups of students of different learning styles, grade levels, ethnicity, or gender, and taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. This procedure allows for simultaneous testing of treatment effects on multiple dependent variables while adjusting group means to compensate for sources of variation that could not be controlled in the experiment, but which are believed to affect the dependent variables. Utilizing the MANCOVA procedure reduces experimental error, results in increased power, and reduces experimental bias caused by between-group differences which are attributed to the independent variables (Kirk, 1982). To simultaneously test the hypothesis that several population means do not differ from a specified set of constants the Hotellings Trace statistic is used. In this study a Hotellings Trace statistic was calculated for the effects of the treatment, effects of the learning style, grade level, ethnicity, and gender; and interaction effects of those variables on the dependent variables. Effect of Treatment The Hotellings Trace statistic for the effects of the teaching approach or treatment on the dependent variables was .12, F (4, 154) = 2.34, p = .05. Table 4-15 contains the data derived from the univariate analysis of effects of the treatment. Since this statistic was significant at the .05 level, a follow-up univariate analysis of covariance was conducted. This follow-up analysis indicated significant differences (p<.001) in the content knowledge gain score of students. This follow-up analysis found that students in the

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84 subject matter only and investigative laboratory groups had significantly higher content knowledge gain than did students in the prescriptive laboratory group (see Table 4-16). Table 4-15 Univariate Analysis of Treatment Effects Source df F p Content Knowledge Gain Score 2 17.45 <.001 Science Process Skill Gain Score 2 18.65 <.001 Note. Hotellings T = .12, F (4, 154) = 2.34, p = .05 Table 4-16 Content Knowledge Gain Score Pairwise Comparisons Group Group M Difference SE p SM PL 5.60 1.04 <.001 SM IL 1.64 1.14 .15 PL IL -3.97 .95 <.001 Significant differences (p <.001) were also discovered in the science process skill gain score of students. Similar to the findings of the content knowledge gain, students in the subject matter only and investigative laboratory groups had significantly higher science process gain scores than did students in the prescriptive laboratory group (see Table 4-17). Table 4-17 Science Process Skill Gain Score Pairwise Comparisons Group Group M Difference SE p SM PL 5.84 1.02 <.001 SM IL 1.66 1.30 .20 PL IL -4.18 1.14 <.001 Effects of Learning Style The Hotellings Trace statistic for the effects of learning style on the dependent variables was .18, F (4, 154) = 3.37, p = .01. Since this statistic was significant at the .05 level, a follow-up univariate analysis of covariance was conducted. This follow-up analysis indicated no significant differences (p = .24) in the content knowledge gain score of students. Furthermore, no significant differences (p = .18) were discovered in the

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85 science process skill gain score of students. Table 4-18 contains data derived from the univariate analysis of effects of the treatment. Table 4-18 Univariate Analysis of Learning Style Effects Source df F p Content Knowledge Gain Score 2 1.458 .236 Science Process Skill Gain Score 2 1.766 .175 Note. Hotellings T = .18, F (4, 154) = 3.37, p = .01 Effects of Demographic Variables No demographic variable had a Hotellings Trace statistic that was significant at the .05 level. Table 4-19 contains the multivariate analysis data. Since no variable was found to significantly contribute to either dependent variable (content knowledge gain score or science process skill gain score), further univariate analysis was not needed. Table 4-19 Multivariate Analysis of Demographic Variable Effects Source Hotellings Trace F p Grade Level .102 1.306 .258 Ethnicity .103 1.316 .253 Gender .022 .868 .424 Effects of Interaction of Variables No interaction of variables analysis yielded a Hotellings Trace statistic that was significant at the .05 level. Since no interaction was found to significantly contribute to either dependent variable (content knowledge gain score or science process skill gain score), further univariate analysis was not needed. Test of Hypotheses To determine if significant differences existed in the content knowledge gain score and science process skill gain score of students taught in classes using the subject matter, prescriptive laboratory, or investigative laboratory approaches, and to determine the effect of student learning styles on those differences, hypotheses were formulated to

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86 guide this study. The decisions to retain or reject the null hypotheses were based upon the findings of the multivariate analysis of covariance and subsequent univariate analysis of covariance procedures used to analyze the data. Results of the test of hypotheses are presented as they pertain to student content knowledge gain and science process skill gain. Hypotheses Related to Content Knowledge Gain HO 1 : There is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Student content knowledge gain score was calculated by subtracting the students content knowledge pretest score from his or her content knowledge posttest score. Table 4-20 contains the summary statistics of gain scores by treatment. Table 4-20 Mean Gain Scores by Treatment Gain Score SM PL IL Content Knowledge 6.27 1.71 5.04 Science Process Skill 2.02 -2.50 3.21 Students taught using the subject matter approach recorded the highest mean content knowledge gain score (M = 6.27). The univariate analysis of covariance revealed significant differences in content knowledge gain score at the alpha level of .05 for content knowledge gain scores between students taught by the three approaches. Based upon these findings, the null hypothesis of no difference in content knowledge gain scores of students taught by using the subject matter, prescriptive laboratory, or investigative laboratory approaches was rejected. HO 2 : There is no difference in the content knowledge gain scores of agricultural education students of different learning styles. Field-Independent learners recorded the highest mean content knowledge gain score (M = 4.80). The univariate analysis of covariance failed to reveal significant

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87 differences in content knowledge gain score at the alpha level of .05 for content knowledge gain scores between students of various learning styles. Based upon these findings, the null hypothesis of no difference in content knowledge gain scores of students of various learning styles failed to be rejected. Table 4-21 contains the summary statistics of gain scores by learning style. Table 4-21 Mean Gain Scores by Learning Style Gain Score FD FN FI Content Knowledge 3.45 3.61 4.80 Science Process Skill -.56 -.44 .77 HO 3 : There is no difference in the content knowledge gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Field-Neutral learners taught using the subject matter approach recorded the highest mean content knowledge gain score (M = 7.50). However, the multivariate analysis of covariance failed to reveal significant differences in content knowledge gain score at the alpha level of .05 for content knowledge gain scores between students taught by the three approaches across learning styles. Therefore, the null hypothesis of no difference in content knowledge gain scores of students of various learning styles taught by using the subject matter, prescriptive laboratory, or investigative laboratory approaches failed to be rejected. Table 4-22 contains the summary statistics of gain scores by treatment across learning styles. Table 4-22 Mean Content Knowledge Gain Scores by Treatment Across Learning Styles SM PL IL Field-Dependent 5.82 1.58 4.00 Field-Neutral 7.50 .57 4.14 Field-Independent 6.50 2.01 6.78

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88 Hypotheses Related to Science Process Skill Gain HO 4 : There is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Students taught using the investigative laboratory approach recorded the highest mean science process skill gain score (M = 3.21). The univariate analysis of covariance revealed significant differences in science process skill gain score at the alpha level of .05 for science process skill gain scores between students taught by the three approaches. Based upon these findings, the null hypothesis of no difference in science process skill gain scores of students taught by using the subject matter, prescriptive laboratory, or investigative laboratory approaches was rejected. Table 4-20 contains the summary statistics of gain scores by treatment. HO 5 : There is no difference in the science process skill gain scores of agricultural education students of different learning styles. Field-Independent learners recorded the highest mean science process skill gain score (M = .77). However, a univariate analysis of covariance failed to reveal significant differences in science process skill gain score at the alpha level of .05 for science process skill gain scores between students of various learning styles. Based upon these findings, the null hypothesis of no difference in science process skill gain scores of students of various learning styles failed to be rejected. Table 4-21 contains the summary statistics of gain scores by learning style. HO 6 : There is no difference in the science process skill gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Field-Independent learners taught using the investigative laboratory approach recorded the highest mean science process skill gain score (M = 4.40). However, a

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89 multivariate analysis of covariance failed to reveal significant differences in science process skill gain score at the alpha level of .05 for science process skill gain scores between students taught by the three approaches across learning styles. Therefore, the null hypothesis of no difference in science process skill gain scores of students of various learning styles taught by using the subject matter, prescriptive laboratory, or investigative laboratory approaches failed to be rejected. Table 4-23 contains the summary statistics of gain scores by treatment across learning styles. Table 4-23 Mean Science Process Skill Gain Scores by Treatment Across Learning Styles SM PL IL Field-Dependent 1.07 -2.72 2.83 Field-Neutral 3.50 -4.17 .60 Field-Independent 3.25 -1.08 4.40 Summary This chapter presented the findings of this study. The findings were organized around the objectives and hypothesis that guided this research. The objectives were: (1) describe the learning styles, ethnicity, and other demographic characteristics of participants in this study; (2) describe the variance in content knowledge gain score attributed to learning styles, ethnicity, and other demographic characteristics; and (3) describe the variance in science process skill gain score attributed to learning styles, ethnicity, and other demographic characteristics. The null hypotheses tested in this study were: (1) there is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach; (2) there is no difference in the content knowledge gain scores of agricultural education students of different learning styles; (3) There is no difference in the content knowledge gain scores of agricultural education students of

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90 different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach; (4) there is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach; (5) there is no difference in the science process skill gain scores of agricultural education students of different learning styles; (6) there is no difference in the science process skill gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. The findings presented in this chapter will be discussed in greater detail in Chapter 5. Additionally, conclusions, recommendations, and implications regarding these findings will also be presented.

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CHAPTER 5 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS The purpose of this study was to determine the effect of investigative laboratory integration on student content knowledge achievement and science process skill achievement across learning styles, gender, and ethnicity. The independent variable in this study was the teaching method used in selected agricultural education classes. The treatment groups utilized one of three levels of treatment: subject matter approach without laboratory experimentation, subject matter approach with prescriptive laboratory experimentation, and subject matter approach with investigative laboratory experimentation. Characteristics that were treated as antecedent variables were student learning style, ethnicity, and gender. Covariates were used to adjust group means in order to compensate for previous knowledge of the subject matter. These covariate measures included pretests for the unit of instruction. The following research objectives and hypotheses guided this study. Objectives 1. Describe the learning styles, ethnicity, and other demographic characteristics of participants in this study. 2. Describe the variance in content knowledge gain score attributed to learning styles, ethnicity, and other demographic characteristics. 3. Describe the variance in science process skill gain score attributed to learning styles, ethnicity, and other demographic characteristics. 91

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92 Null Hypotheses All statistical analyses that involved significance testing were tested at an alpha level of .05. This equates to a five percent chance of a Type I error. A Type I error occurs if significance was determined when in fact there was none. HO 1 : There is no difference in content knowledge gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 2 : There is no difference in content knowledge gain scores of agricultural education students of different learning styles. HO 3 : There is no difference in content knowledge gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 4 : There is no difference in science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. HO 5 : There is no difference in science process skill gain scores of agricultural education students of different learning styles. HO 6 : There is no difference in science process skill gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Methods This study was conducted using a quasi-experimental design referred to by Campbell and Stanley (1963) as the nonequivalent control group design. The independent variable in this study was the teaching method used in an introductory agriscience course. The dependent variables were student content knowledge achievement and science process skill achievement. Antecedent variables were student learning style, ethnicity, and gender. Student content knowledge pretest score, and science process skill pretest score were used as covariate measures.

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93 The population for this study was Florida students enrolled in an introductory agriscience course. A purposively selected sample based upon the ability of the teacher to effectively deliver all three teaching approach treatments was selected from the population. After being selected for the study, each teacher was assigned one of the three treatments. Following the suggestion made by Boone (1988) for conducting teaching method studies using teachers to deliver the treatment, precautions were taken to ensure teacher conformity to the assigned teaching approach. Professional development in the form of personal instruction and a videotape containing instructions and a lesson demonstration was provided for each teacher in the study. All materials needed by the teacher to deliver the treatment (lesson plans, handouts, assessment instruments, etc.) were provided by the researcher. Furthermore, the teachers audio recorded each lesson in which the treatment was delivered. These audio tapes were then analyzed to determine the level to which the treatment was delivered. Students in classes in which the assigned teaching approach had not been properly utilized were removed from the study. The researcher developed instructional plans appropriate to the teaching methods used in each level of the treatment. The content of the unit was designed to address Florida Student Performance Standard 06.0 for the Agriscience Foundations I course (Florida Department of Education, 2002), specifically plant germination and plant functions. The subject matter to be taught was consistent among all three sets of instructional plans. The instructional plans were evaluated for content validity by a panel of experts from the Agricultural Education and Communication Department at the University of Florida.

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94 Instruments to collect data for the variable of content knowledge achievement were developed by the researcher. This instrument was determined to be a valid and reliable instrument through review by an expert panel and the calculation of a post-hoc reliability coefficient of .92 using the Kuder-Richarson 20 formula. Parallel forms of this instrument were used prior to (pretest) and immediately following (posttest) the administration of the treatment. The Test of Integrated Process Skill (TIPS), developed by Dillashaw and Okey (1980), was used to assess the science process skill ability of students. Parallel forms of this instrument were used to collect both pretest and posttest data. This instrument was found to have a post-hoc reliability coefficient of .72 using the Kuder-Richarson 20 formula. The Group Embedded Figures Test (Witkin et al., 1971) was used to measure the student learning style. Data concerning the variables of student ethnicity, gender, and other demographic information were reported to the research by the schools student services department from student records. Data were analyzed using the SPSS version 12.0 for Windows software package. Analysis of the first objective involved descriptive statistics and included frequencies, means, and standard deviations. The next two objectives were examined using backward regression analyses. All hypotheses were tested using multivariate analysis of covariance (MANCOVA). Univariate analysis of covariance (ANCOVA) was used as a follow-up procedure, when appropriate. Summary of Findings The findings of this study are summarized using the objectives and hypotheses presented in earlier chapters.

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95 Objective One The first objective sought to describe the purposively selected sample of this study. A majority (62.7%) of the students involved in this study were in the ninth grade. The second largest grade level represented was the tenth grade (19.9%). The remainder of the sample was in the eleventh grade (12.1%) and the twelfth grade (5.3%). Variations in the demographic make-up of each of the treatment groups were noted. All results should be interpreted with that caution in mind. The majority (66.5%) of students in the study were male. A majority (56.0%) of the students selected White, non-Hispanic as their ethnic group. The next largest group of participants was Hispanic (34.5%), followed by Black (7.9%) and Other (1.6%). Variations in the ethnic composition of each of the treatment groups were noted. All results should be interpreted with that caution in mind. The mean Group Embedded Figures Test (GEFT) score for respondents of this study was 7.6 (SD = 4.74). A majority (60.7%) of students were categorized as field-dependent in their learning style. Field-independent learners constituted the second largest group (23.2%) followed by field-neutral learners (16.1%). Variations in the learning style composition of each of the treatment groups were noted. All results should be interpreted with that caution in mind. Student content knowledge achievement was determined using the researcher developed content knowledge achievement pretest and posttest instruments. The maximum possible score on these parallel instruments was 50. The pretest mean was 16.39 (SD = 5.04) across all students. A posttest mean of 20.59 (SD = 6.79) was reported across all respondents. The mean content knowledge gain score was 3.93 (SD = 6.15).

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96 These means are extremely low. The posttest mean indicated that on average students only answered approximately 41% correctly. The Test of Integrated Process Skills was used to determine the science process skill level of students. This instrument is considered a standardized test and was developed by Dillashaw and Okey (1980). Parallel versions of this instrument were given to the students at two collection points in the study (pretest and posttest). The maximum score of this instrument is 36. The pretest mean was 15.57 (SD = 5.66) across all students. A posttest mean of 15.81 (SD = 6.66) was reported across all respondents. The mean content knowledge gain score was -0.17 (SD = 6.33). These means are extremely low. The posttest mean indicated that on average students only answered approximately 44% correctly. The relationships between the variables discussed above were also examined. A very high correlation was found between content knowledge posstest score and content knowledge gain score (r = .70). Substantial correlations were discovered between content knowledge posttest score, content knowledge pretest score (r = .50), and science process skill posttest (r = .55). A substantial correlation was also found between science process skill posttest score and science process skill gain score (r= .65). A moderate correlation was discovered between content knowledge posttest score and science process skill pretest score (r = .46). Moderate correlations were also discovered between content knowledge pretest score and science process skill pretest score (r = .48) and science process skill posttest score (r = .43). Moderate correlations were also discovered between science process skill pretest score and content knowledge posttest (r = .44), science process skill posttest score (r = .47), science process gain score (r = -.36),

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97 academic performance rating (r = .41), and GEFT score (r = .42). Additionally, moderate correlations were discovered between GEFT score and science process skill posttest score (r = .38) and academic performance rating (r = .32). Several variables with low correlations were observed. Objective Two This objective sought to describe the variance in content knowledge gain score attributed to leaning styles, ethnicity, and other demographic characteristics. The backward regression procedure was selected to address this objective. A model consisting of field-dependent learning style (t = -2.35, p = .02), subject matter treatment group (t = 2.40, p = .02), prescriptive laboratory treatment group (t = -3.86, p <.001), ethnicity (t = 2.27, p = .02), science process skill pretest score (t = 5.07, p <.001), and content knowledge pretest score (t = -7.77, p <.001) was identified that accounted for 33% of the variance in content knowledge gain score. Objective Three This objective sought to describe the variance in science process skill gain score attributed to leaning styles, ethnicity, and other demographic characteristics. The backward regression procedure was selected to address this objective. A model consisting of field-dependent learning style (t = -3.01, p = .003), prescriptive laboratory group membership (t = -5.30, p <.001), gender (t = -2.52, p = .01), science process skill pretest score (t = -6.51, p <.001), and content knowledge pretest score (t = 2.38, p =.02) was identified that accounted for 36% of the variance in science process skill gain score. Null Hypothesis One The first null hypothesis for this study was that there is no difference in the content knowledge gain scores of agricultural education students taught using the subject matter,

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98 prescriptive laboratory, or investigative laboratory approach. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for group effects on the dependent variables was .12, F (4, 154) = 2.34, p = ..05. The effect size was .06 and the power was .67. The follow up univariate analysis of covariance revealed significant differences in content knowledge gain score between students in the various treatment groups. Therefore the null hypothesis was rejected. Null Hypothesis Two The second null hypothesis for this study was that there is no difference in the content knowledge gain scores of agricultural education students of various learning styles. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for learning style effects on the dependent variables was .18, F (4, 154) = 3.37, p = .01. The effect size was .08 and the power was .84. The follow up univariate analysis of covariance failed to reveal significant differences in content knowledge gain score between students of various learning styles. Therefore the null hypothesis was not rejected. Null Hypothesis Three The third null hypothesis for this study was that there is no difference in the content knowledge gain scores of agricultural education students of various learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for group effects on the dependent variables was .07, F (8, 154) = .65, p = .73. The effect size was .03 and the power was .29. This multivariate analysis of covariance failed to reveal significant differences in content knowledge gain score between students in the

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99 various treatment groups across learning styles. Therefore, the null hypothesis failed to be rejected. Null Hypothesis Four The fourth null hypothesis for this study was that there is no difference in the science process skill gain scores of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for group effects on the dependent variables was .12, F (4, 154) = 2.34, p = .05. The effect size was .06 and the power was .67. The follow up univariate analysis of covariance revealed significant differences in science process gain score between students in the various treatment groups. Therefore, the null hypothesis was rejected. Null Hypothesis Five The fifth null hypothesis for this study was that there is no difference in the science process skill gain scores of agricultural education students of different learning styles. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for learning style effects on the dependent variables was .18, F (4, 154) = 3.37, p = .01. The effect size was .08 and the power was .84. The follow up univariate analysis of covariance failed to reveal significant differences in science process skill gain score between students of various learning styles. Therefore, the null hypothesis was not rejected. Null Hypothesis Six The sixth and final null hypothesis for this study was that there is no difference in the science process skill gain scores of agricultural education students of different learning styles taught using the subject matter, prescriptive laboratory, or investigative

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100 laboratory approach. The MANCOVA procedure was used to test this hypothesis. The Hotellings Trace statistic for group effects on the dependent variables was .07, F (8, 154) = .65, p = .73. The effect size was .03 and the power was .29. This multivariate analysis of covariance failed to reveal significant differences in science process skill gain score between students in the various treatment groups across learning styles. Therefore, the null hypothesis failed to be rejected. Conclusions The sample used in this study was not randomly drawn from the population. With this limitation in mind, and based on the findings of this study, the following conclusions were drawn. 1. Participants in this study were predominantly White (56.0%), male (66.5%), and enrolled in the ninth grade (62.7%). Hispanics comprised 34.5% of the participants. The majority of students were field-dependent in their learning style (60.7%). 2. Of the students who participated in this study, white, non-Hispanic students with a field-independent learning style taught using the subject matter approach with higher science process skill pretest scores and lower content knowledge pretest scores tended to have higher content knowledge gain scores. 3. Of the students who participated in this study, female students with a field-independent learning style taught using the subject matter or investigative laboratory approach with lower science process skill pretest scores and higher content knowledge pretest scores tended to have higher science process gain scores. 4. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students taught using the subject matter approach or the investigative laboratory approach to teaching tended to have the higher content knowledge gain scores as compared to students taught using the prescriptive laboratory approach. 5. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar content knowledge gain scores. 6. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar content knowledge gain scores regardless of teaching method used.

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101 7. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students taught using the subject matter approach or the investigative laboratory approach to teaching tended to have higher science process skill gain scores, as compared to students taught using the prescriptive laboratory approach. 8. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar science process skill gain scores. 9. When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar science process skill gain scores regardless of teaching method used. Discussion and Implications Objective One: Describe the Learning Style, Ethnicity, and Other Demographic Characteristics of Participants in This Study. Conclusion: Participants in this study tended to be White males in the ninth grade. They tended to be field-dependent in their learning style It was expected that the majority of participants in this study would be in the ninth grade. Since the population for this study was students enrolled in the Agriscience Foundations I course in Florida high school agricultural education programs. As the name implies, this course was an introductory course in agricultural education, and as such, is the first agricultural education course in which students enroll upon entering high school. The finding that approximately 17% of the students in the study were upperclassmen (eleventh and twelfth graders) was somewhat surprising due to the introductory nature of the course. However, since this course counts as a science credit toward graduation, these upperclassmen may be enrolling in this course for that reason. If so, this might indicate that upperclassmen taking Agriscience Foundations I are not in a college preparatory curriculum, since those students would likely have completed their introductory science requirements by this time. Another possible explanation may be that these students are only looking for what they perceive to be a less difficult science credit

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102 course. Other possible explanations could be that due to more strict graduation requirement or possibly school overcrowding, these upperclassmen were not able to enroll in this introductory course at an earlier date. Further research is needed to understand the motivation of students enrolling in this type of agricultural education course. The finding that most students in this study were field-dependent in their learning style was not surprising due to previous learning style research with students of similar ages. This finding concurred with Cox, Sproles, and Sproles (1988) finding that students 14-15 years of age possess a learning style with characteristics similar to those identified in this study as of field-dependent learners. The finding that older students in the study were also field-dependent differs from findings of earlier studies concerning learning styles at the high school level (Dyer, 1995; Howard & Yoder, 1987; Witkin et al., 1977). However, Cox et al. opined that student learning style becomes more concrete as the number of agricultural education courses enrolled in increase (e.g., they become more concrete in learning style as they get older). Since this is most likely the first agricultural education course for these older students, this may explain why the older students exhibited a more field-dependent (abstract) learning style. However, further research in this area is warranted. A substantial correlation (r = .50) was found between student content knowledge pretest and posttest scores, indicating that students who had a higher level of content knowledge entering the study were able to achieve higher scores on the posttest. This may indicate the presence of a predisposition to learn science-related materials. Further investigation in this area is needed to better understand this phenomenon.

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103 The finding that most students in the study categorized their ethnicity as White is not surprising. The majority of students enrolled in public schools in the state of Florida are also categorized as White (Florida Department of Education, 2003). Hispanics were the second most represented ethnic group in this study followed by Blacks. This differs slightly from the state enrollment totals. The number of individuals identifying themselves as Black was the second largest ethnic group with Hispanics being third. Research is needed to determine why black students are not enrolling in agricultural education courses at the high school level. Overall, the posttest scores for all students involved in the study were very low. Further investigation is needed to address why students achieved so poorly. It is of concern when a great deal of time is spent in teaching a unit of instruction and the result is a small amount of knowledge gain. Objective Two: Describe the Variance in Content Knowledge Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics. Conclusion: Of the students who participated in this study, white, non-Hispanic students with a field-independent learning style taught using the subject matter approach with higher science process skill pretest scores and lower content knowledge pretest scores tended to have higher content knowledge gain scores. The finding that students with less prior knowledge in the content area had higher content knowledge gain scores at the conclusion of instruction is contradictory to the findings of Roberts (2003). However, students with greater science process skill achievement prior to instruction showed higher content knowledge gain. Likewise, student science process skill pretest score was moderately correlated (r = .44) with content knowledge posttest score. Gender did not contribute significantly to explaining the variance in content knowledge achievement. However, learning style was found to play a role in knowledge

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104 gain. Students with a field-independent learning style were predicted to have more than double (2.25) the content knowledge gain as compared to field-dependent learners when all other variables are controlled. Previous research regarding the influence of learning styles on achievement was inconclusive. These findings, however, are inconsistent with the studies that reported no difference in gain scores based on learning styles (Day, Raven, & Newman, 1998; Freeman, 1995; Roberts, 2003; Shih & Gamon, 2001). The regression equation predicted that white, non-Hispanic students would have gain scores 2.14 times greater than that of minority students when all other variables are held constant. Further research is needed to better understand the cause of this gain discrepancy. Of particular interest is the effect of socioeconomic status of students on achievement. Are ethnicity and socioeconomic status coterminous as Abbot and Joirman (2001) suggest? If that is the case, what can educators do to mitigate the effect? Objective Three: Describe the Variance in Science Process Skill Gain Score Attributed to Learning Styles, Ethnicity, and Other Demographic Characteristics. Conclusion: Of the students who participated in this study, female students with a field-independent learning style taught using the subject matter or investigative laboratory approach with lower science process skill pretest scores and higher content knowledge pretest scores tended to have higher science process gain scores. Field-independent learners tend to more easily be able to organize materials and solve problems (Dyer, 1995). Dyer further noted that this type of learner favors more scientific areas such as mathematics, physics, chemistry, and biology. Furthermore, Dyer opined that these learners may perform better when allowed to develop their own strategies to address an issue. With these characteristics in mind, it is not surprising that field-independent learners would tend to have higher science process skill achievement. A review of the objectives of the Test of Integrated Process Skills (Dillashaw and Okey, 1980) reveals that many of these traits lead to greater science process skill ability. This

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105 may indicate a predisposition of some individuals to learn science-related material. Further research is needed to investigate the possible presence of this predisposition. Similar to the finding in objective two, students with lower initial levels of science process skill were found to have higher science process gain scores. This may be due to the fact that these students had more room to grow in this area, compared to their counterparts who entered the treatment with higher levels of science process skill. It is intriguing to note that the regression equation predicts that female students are likely to attain 2.18 times the science process gain scores as compared to males, when all other variables are held constant. This contradicts the often commonly held notion that females students under-perform their male counterparts in the area of science. However, it should be noted that agriculture often attracts females who tend to be field-independent in their learning style and therefore does not represent a normal distribution. Further research should be conducted to explain this large difference in gain between the genders. Hypotheses Related to Content Knowledge Gain Null Hypothesis One: There is no difference in the content knowledge gain score of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students taught using the subject matter approach or the investigative laboratory approach to teaching tended to have the higher content knowledge gain scores as compared to students taught using the prescriptive laboratory approach Null Hypothesis Two: There is no difference in the content knowledge gain score of agricultural education students of various learning styles.

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106 Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar content knowledge gain scores. Null Hypothesis Three: There is no difference in the content knowledge gain score of agricultural education students of various learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar content knowledge gain scores regardless of teaching method used. The findings of this study suggest that students taught using either the subject matter approach or investigative laboratory approach to teaching had higher content knowledge gain scores than students taught using the prescriptive laboratory treatment level. This finding did not support the research conducted by Osborne (2000) involving similar secondary students. Osborne reported that students who participated in prescriptive laboratory activities developed higher levels of content knowledge achievement than those using investigative laboratories. Therefore, a decision must be made by the practicing teacher of which approach to employ in their classroom. Whereas it was reported by the teachers involved in this study that the investigative approach took a substantially longer period of time to implement than did the subject matter approach (1900 minutes, as compared to 1410 minutes, respectively), it would follow that most teachers would select the shorter time frame. However, upon investigation as to the level of cognitive ability at which content knowledge was assessed, the vast majority of questions on the assessment instruments addressed only the lower levels of Blooms Taxonomy (Anderson & Krathwohl, 2001). While this is similar in nature to the questions found on many of the standardized test instruments that are common in todays educational environment, the question remains as to how these teaching approaches affect student understanding at the higher levels of Blooms

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107 Taxonomy. Further research is needed to assess this question. Whereas it is understood that knowledge at the lower levels is needed to form a strong foundation upon which to build, it is equally important to address knowledge and understanding at the higher levels. Learning styles of students were not found to have significant influence on content knowledge gain score, either alone or in interaction with level of treatment (teaching method). This finding concurred with the research conducted by Garton, Spain, Lamberson, and Spiers (1999) involving secondary students. However, Dyer and Osborne (1996a) reported finding differences in student achievement based on learning style. This study adds another dimension to the investigation of the effect of learning style on content knowledge achievement. The mean Group Embedded Figures Test (GEFT) score was 7.6 (SD = 4.74). This indicates that, in general, students in this study were strongly field-dependent. The national grand mean of this learning style instrument, as reported by its authors (Witkin et al., 1971), was 11.3. Although no statistical significance was found across learning styles, further investigation into the influence of learning styles at the extremes of the scale may be warranted. Anecdotally, it was apparent that teachers in this study had not used the investigative approach before since they were not familiar with investigative or inquiry based teaching approaches. Therefore it is likely that the Hawthorne effect was a concern. The novelty of this new teaching method may have influenced the effectiveness of the treatment. It was noted that participating teachers that were assigned to the subject matter or prescriptive laboratory groups were much more familiar, and therefore more comfortable, with the teaching method. The lack of familiarity and teaching confidence

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108 in teachers assigned the investigative laboratory grouping may have had a negative effect on student gain scores in both content knowledge and science process skill. All findings of this study should be interpreted with this concern in mind. Although the difference in content knowledge gain score between levels of treatment was found to be statistically significant, further analysis showed that this finding had an effect size of only .06 and a power of .67. This means that the effect of the treatment resulted in a .06 standard deviation increase in content knowledge gain. Using the classification taxonomy suggested by Cohen (1988) for effect size, this is considered a small effect. Hypotheses Related to Science Process Skill Gain Null Hypothesis Four: There is no difference in the science process skill gain score of agricultural education students taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students taught using the subject matter approach or the investigative laboratory approach to teaching tended to have the higher levels of science process skill gain scores as compared to students taught using the prescriptive laboratory approach Null Hypothesis Five: There is no difference in the science process skill gain score of agricultural education students of various learning styles. Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar science process skill gain scores. Null Hypothesis Six: There is no difference in the science process skill gain score of agricultural education students of various learning styles taught using the subject matter, prescriptive laboratory, or investigative laboratory approach. Conclusion: When taught using the subject matter, prescriptive laboratory, or investigative laboratory approaches, students of varying learning styles had similar science process skill gain scores regardless of teaching method used.

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109 The findings of this study suggest that students taught using the investigative laboratory approach or the subject matter approach to teaching had higher science process skill gain scores than students taught using the prescriptive laboratory treatment level. This finding did not support the research conducted by Osborne (2000) involving similar secondary students. Osborne reported that students who participated in prescriptive laboratory activities developed higher levels of science process skill than those using investigative laboratories. Furthermore, Germann (1989) reported no significant difference in the science process skill ability of ninth and tenth grade students who were taught using techniques similar to those used in the investigative laboratory group when compared to traditional teaching methods. In light of these conflicting findings, further research into the effect of teaching method on student science process skill development is warranted. Learning style of the student was not found to have significant influence on science process skill gain score either alone or in interaction with level of treatment (teaching method). However, GEFT score was found to be moderately correlated with both science process skill pretest (r = .42) and science process skill posttest (r = .38). As stated earlier, the mean Group Embedded Figures Test (GEFT) score was 7.6 (SD = 4.74). This indicates that, in general, this group was strongly field-dependent. Dyer (1995) stated that field-dependent learners tend to work better in situations where structure is provided for them, such as in the subject mater and prescriptive laboratory methods. Field-independent learners on the other hand tend to prefer a hypothesis-testing approach to learning and are better able to provide their own structure in learning activities such as in the investigative laboratory approach. Therefore, it stands to reason that field

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110 independent learners would enjoy and perhaps experience more success in classrooms in which the investigative approach was utilized. Further investigation into this phenomenon is suggested. As was the case with content knowledge gain, the difference in science process skill gain scores between levels of treatment was found to be have an effect size of .06 and a power of .67, which is considered a small effect (Cohen ,1988). Recommendations for Practitioners Based on the findings of this study, the following recommendations were made for practitioners in secondary agricultural education: 1. A combination of teaching methods should be used to assist students in increasing both content knowledge and science process skill. Whereas different teaching methods were identified as being the most effective in these two areas, they should likely be used in combination. Although the individual differences in student learning style were present, no one teaching method produced a high level of achievement of gain across all groups. 2. Whereas students of varying learning styles recorded similar levels of achievement in both content knowledge and science process skill, teachers may utilize these teaching methods in their classrooms to address all learning styles. 3. Anecdotally, it was found that teachers were not familiar with investigative or inquiry based teaching approaches. Practicing teachers of agriscience in secondary schools should participate in professional development on how to properly incorporate the teaching methods utilized in this study. 4. Agriscience courses should include direct instruction on the science process skills. This instruction should include a focus on the development of the integrated process skills with a review of the basic science skills. Recommendations for Further Research Whereas the variables addressed in this study were able to describe 33% and 36% of the variance in content knowledge and science process skill gain score, respectively, further research is needed to attempt to understand the unaccounted for variance.

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111 Therefore, the following recommendations for further research in this area are provided to act as a guide in this pursuit. 1. As a clinical study, this study should be replicated using procedures that allow a higher degree of randomization and ultimately more generalizability. As noted by Edwards (2003), the research base in agricultural education is dominated by descriptive type research. More research using experimental methods are needed to assist the profession in advancing in the area of agriscience achievement. 2. Research on the relationship between teaching methods, content knowledge, and science process skill achievement of high school students in agricultural education programs should continue. This study should act as a guide with future research is planned and conducted in this area. 3. Moderate correlations were discovered between learning style and science process skill test scores. Additional information on this correlation was not found in the research literature. This relationship warrants further investigation to better explain this phenomenon. 4. In this study, the teaching methods utilized as treatments were used only to deliver content material in the area of plant germination. It is recommended that this study be replicated using other content areas as the focus to determine it this effects the findings. 5. The sample for this study consisted of primarily ninth grade students in an introductory agriscience course. It is recommended that this study be replicated on a wider student population in agricultural education. This type of study should investigate the effect of age and number of agriscience courses has on student achievement in the area of content knowledge achievement and science process skill development. 6. This study was conducted over a relatively short time period. It is recommended that this study be replicated including a longer treatment period to investigate the effectiveness of these methods more thoroughly. Furthermore, it was noted by teachers that students were not familiar with learning in a classroom environment that utilized the investigative approach. By increasing the treatment time, students in this treatment group could become more accustomed to the teaching method. 7. This study examined only the effect of the teaching methods on content knowledge achievement and science process skill achievement, as measured directly following instruction. It is recommended that this study be replicated to investigate the effects of these treatments on both short-term and long-term retention of content knowledge and science process skill.

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112 8. This study did not assess student attitude toward the various methods of instruction. Further research should be conducted to determine how these various teaching method effect student motivation and self-efficacy. 9. Given the number of upper classmen that were found to be enrolled in this introductory agriscience course, further research should be conducted to determine the effect of awarding science credit for graduation in agriscience courses on student enrollment demographics.

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APPENDIX A TREATMENT DELIVERY ANALYSIS SCORESHEETS Subject Matter Approach Teacher ID Number: ______________ Lesson Number: _______________ Points Awarded Points Allowed _______ (2 pts) 1. Was new subject matter provided in small chunks? _______ (2 pts) 2. Was student progress/understanding checked following each presentation? How? ____ Oral questions ____ Student written summaries (journals) ____ Think/pair/share ____ Group discussions ____ Written exam/quiz ____ Student worksheet(s) ____ Other: _______ (2 pts) 3. Did the instructor provide students with feedback? How? ____ Oral comments ____ Written comments _______ (2 pts) 4. Were students provided an opportunity for independent practice? _______ (2 pts) 5. Did the instructor provide a review of new subject matter? _______ (5 pts) 6. Were laboratory exercises used as part of this lesson 113

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114 Prescriptive Laboratory Approach Teacher ID Number: ______________ Lesson Number: _______________ Points Awarded Points Allowed _______ (1 pts) 1. Was new subject matter provided in small chunks? _______ (1 pts) 2. Was student progress/understanding checked following each presentation? How? ____ Oral questions ____ Student written summaries (journals) ____ Think/pair/share ____ Group discussions ____ Written exam/quiz ____ Student worksheet(s) ____ Other: _______ (4 pts) 3. Did the instructor provide students with step-by-step instructions on how to complete the laboratory activity? _______ (2 pts) 4. Did the instructor provide students with feedback? How? ____ Oral comments ____ Written comments _______ (2 pts) 5. Did the instructor provide a review of new subject matter?

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115 Investigative Laboratory Approach Teacher ID Number: ______________ Lesson Number: _______________ Points Awarded Points Allowed _______ (1 pts) 1. Was new subject matter provided in small chunks? _______ (1 pts) 2. Was student progress/understanding checked following each presentation? How? ____ Oral questions ____ Student written summaries (journals) ____ Think/pair/share ____ Group discussions ____ Written exam/quiz ____ Student worksheet(s) ____ Other: _______ (4 pts) 3. Did the instructor allow students to design their own procedures to complete the laboratory activity? _______ (2 pts) 4. Did the students report their results to the rest of the class? _______ (1 pts) 5. Did the instructor provide students with feedback? How? ____ Oral comments ____ Written comments _______ (1 pts) 6. Did the instructor provide a review of new subject matter?

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APPENDIX B INSTRUCTIONAL PLANS Subject Matter Approach Course: Agriscience Foundations I Lesson: Scientific Method (06.00.SM) Objectives: 1. Identify the steps involved in the scientific method of investigation. 2. Define common terms used in agriscience research. 3. Properly report scientific findings. Student Performance Standards Addressed: 04.01 04.05 04.06 Equipment, Supplies, References, and Other Resources: References : Cooper, E. L. & Burton, L. D. (2004) Agriscience: Fundamentals and applications (3 rd Edition). Albany, NY: Delmar. (Unit 1). Osborne, E. W. (1994). Biological science applications in agriculture. Danville, IL: Interstate Publishers, Inc. (Chapter 1). Handouts : The Experimentation Process handout Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.00.A The Scientific Method o TM: 06.00.B Agriscience Terms o TM: 06.00.C Guidelines for Constructing Charts and Graphs Equipment & Supplies : Audio recorder Audio tapes 116

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117 Teacher Directions Content Outline and/or Procedures REVIEW None new unit INTEREST APPROACH Push record on audio recorder Ask the students to explain the process by which scientists conduct investigations. Ask them to create a step by step procedure. Then ask for volunteers to share their procedure with the rest of the class. Compare student examples with the procedure suggested in the lesson. OBJECTIVES 1. Identify the steps involved in the scientific method of investigation. TM: 06.00.A The Scientific Method A. The scientific method has five steps. 1. Define the problemusually stated as a question. a. What do you want to know? 2. Gather data (facts and information) about the problem. a. Summarize past experiences. b. Review other research results. 3. Suggest possible answers or solutions. a. A hypothesis is a prediction of the results of an experiment. b. Write the hypothesis before beginning the experiment. 4. Test the hypothesis. a. Conduct an experiment to test the hypothesis. b. Summarize the data collected in organized charts or tables. 5. Evaluate the results. a. Examine the findings of the experiment. b. Draw conclusions or judgments made on the basis of the findings. 2. Define common terms used in agriscience research. TM: 06.00.B Agriscience Terms B. Key terms used in agriscience experiments 1. Independent variable : Will affect another variable a. Known as treatment 2. Dependent variable : Observed variable; expected to change due to independent variable 3. Replication exact duplication a. Allows for validation 3. Properly report scientific findings C. Data may be summarized and reported in many different ways.

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118 Teacher Directions Content Outline and/or Procedures TM: 06.00.C Guidelines for Constructing Charts and Graphs 1. Descriptive statistics are one common method. Common descriptive statistics are: a. Means which are averages b. Frequency distributions which are simply counts of how many times something occurred. c. Percentages 2. Data can be visually summarized using charts and graphs. When constructing a graph, there are certain guidelines to follow: a. The independent variable (X) is reported on the horizontal axis (x-axis). b. The dependent variable (Y) is reported on the vertical axis (y-axis). c. Be sure to label the axis and title the graph. REVIEW/SUMMARY Use questioning to determine if students understand the content material of this lesson APPLICATION

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119 Course: Agriscience Foundations I Lesson: Examining Plant Structures and Functions (06.01.SM) Objectives: 4. Describe the cellular structure of plants. 5. Identify the major parts of plants and explain their functions. 6. Distinguish between plants based on seed cotyledons. 7. Explain the absorption and transport systems of plants. Student Performance Standards Addressed: 06.01: Describe the structure functions of plant parts including roots, stems, leaves, and flowers. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.01.A Major Parts of a Plant Cell o TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers o TM: 06.01.C Parts of a Typical Stem o TM: 06.01.E Specialized Stems o TM: 06.01.F Kinds of Roots o TM: 06.01.G Leaf types o TM: 06.01.H Comparison of Monocot and Dicot Seed o TM: 06.01.K Arrangement of Tissues in Stems o TM: 06.01.L Roots o TM: 06.01.M Absorption o TM: 06.01.N Stomata Equipment & Supplies : Plant specimen (Interest Approach) Audio recorder Audio tapes Teacher Directions Content Outline and/or Procedures REVIEW None new unit

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120 Teacher Directions Content Outline and/or Procedures INTEREST APPROACH Push record on audio recorder Bring a small plant specimen (about 18 inches long) that has been pulled up so that leaves, stems, and roots are obvious. A specimen with flowers and/or fruit is preferred. Ask students to name the different parts of the specimen. As they do, have them describe the function of the part and how it is useful to humans. Move from the interest approach into the objectives and anticipated problems for the lesson. OBJECTIVES 1. Describe the cellular structure of plants. I. Cells are the structural basis of all living organisms. A. A cell is a tiny structure that forms the basic building blocks of plants. TM: 06.01. A Major Parts of a Plant Cell 2. Protoplasm in cells carries out life processes. B. Plants are multi-cellular organisms, meaning that they have many cells. 1. Some cells have specific functions. 2. Cell specialization is the presence of cells that perform unique activities for a plant. (Flowers, leaves, roots, and stems are made of specialized cells.) C. Cells are formed into groups that work together. 1. Tissue is formed by groups of cells that are alike in activity and structure. 2. An organ is formed by tissues that work together to perform specific functions. 3. An organ system is a group of organs that works together to perform a function. D. Cell structure is the organization of the material that forms a cell. 1. Plant cells have three major parts: wall, nucleus, and cytoplasm. 1. All organisms are made of one or more cells.

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121 Teacher Directions Content Outline and/or Procedures 2. The cell wall surrounds the cell and controls the movement of materials into and out of the cell. 3. The nucleus is near the center of a cell and contains protoplasm, chromosomes, and other structures that control cell activity. 4. The cytoplasm is a thick solution inside the cell wall surrounding the nucleus. 5. Plant cells have many additional parts, including: chloroplasts, nucleolus, vacuole, mitochondria, and golgi body. 2. Identify the major parts of plants and explain their functions. TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers TM: 06.01.C Parts of a Typical Stem TM: 06.01.E Specialized Stems II. Plants are comprised of vegetative and reproductive parts. A. The major vegetative parts of plants are stems, leaves, and roots. 1. A stem is the central axis that supports the leaves, connects them with the roots, and transports water and other materials between the leaves and roots. Stems vary widely in appearance based on the species of plant. Stems may be vertical or horizontal and modified for climbing and to store water and food. Several specialized kinds of stems are important: a. RhizomeA rhizome is an underground stem that grows horizontally. It may grow adventitious roots and stems to develop as a separate plant. Examples include iris and wild ginger. b. TuberA tuber is an enlarged part of a stem that grows underground. A tuber can develop into a separate plant. Examples include potatoes and yams. c. TendrilA tendril is a threadlike leafless growth on a stem that attaches itself around other stems and objects. Tendrils typically grow in a spiral shape. After attaching itself, it holds the stem in position. Vines and climbing plants often have tendrils. Examples include sweet peas and cucumbers. d. StolonA stolon is an above ground stem that grows horizontally and propagates new plants.

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122 Teacher Directions Content Outline and/or Procedures TM: 06.01.F Kinds of Roots TM: 06.01.G Leaf types TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers Strawberries are well known as examples of plants that multiply using stolons. e. BulbA bulb is an underground food-storage organ consisting of flattened, fleshy stem-like leaves with roots on the lower side. Examples of bulbs are onions and daffodils. f. CormA corm is a food storage structure at the end of a stem that grows underground. It is an enlarged or swollen stem base. Examples include gladiolus and crocus. g. CladophyllA cladophyll is a leaflike branch that resembles a leaf. It is also called a cladode. A cladophyll functions much like a leaf. 2. A root is the part of a plant that grows in the soil or other media. Roots anchor plants, absorb water and minerals, and store food. The root system structure varies widely depending on the species of plant. Overall, roots can be classified as two major types: a. FibrousA fibrous root system is made of many small roots and spread throughout the soil. b. TaprootA taproot system is made of one primary root with a number of small secondary roots. 3. A leaf is typically a large, flat, green organ attached to the stem. Leaves carry out photosynthesis, transpiration, and may store food. Shape, arrangement, and other features vary widely with the species of plant. There are two major kinds of leaves and three major types of arrangements: a. SimpleA simple leaf has only one blade. b. CompoundA compound leaf is divided into two or more leaflets c. Leaf attachment also varies. This refers to the spacing and arrangement of leaves on the stem of a plant. The major kinds of attachment are:

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123 Teacher Directions Content Outline and/or Procedures (1) AlternateAlternate leaf arrangement is one leaf at each node on a stem. (2) OppositeOpposite leaf arrangement is two leaves are attached at nodes opposite each other. (3) WhorledWhorled leaf arrangement is three or more leaves are at each node. B. The major reproductive parts of plants are flowers, seed, and fruit. 1. A flower is a part containing the reproductive organs. The types of flowers vary considerably. In general, flowers produce pollen and ovules. Fertilization occurs when a pollen cell unites with an ovule. 2. Seed are formed by fertilized ovules and contain new plant life. 3. Fruit are the ovaries which develop to protect and nourish the developing seed. The kinds and nature of fruit vary widely. 3. Distinguish between plants based on seed cotyledons. TM: 06.01.H Comparison of Monocot and Dicot Seed III. A cotyledon is the fleshy structure within a seed that contains food for a developing embryo. A. Depending on the plant species, a seed may have one or two cotyledons. B. A plant species producing seed with one cotyledon is a monocotyledon, or monocot. 1. All grasses are monocots. Corn, wheat, oats, Bermuda grass, and sugarcane are examples of monocots. 2. Monocot plants have long, narrow leaves with parallel veins. All leaves branch from the main stem. 3. Stems are non-woody and tend to have a large area of pith in the center. C. A plant species producing seed with two cotyledons is a dicotyledon, or dicot. 1. All plants other than grasses are dicots. Soybeans, trees,

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124 Teacher Directions Content Outline and/or Procedures lettuce, sunflowers, and petunias are examples of dicots. 2. Dicot plants have broad leaves with a net-type of veins. 3. Stems are often long and branching. They may be woody or non-woody, depending on the plant species. 4. Explain the absorption and transport systems of plants. TM: 06.01.K Arrangement of Tissues in Stems TM: 06.01.L Roots TM: 06.01.M Absorption TM: 06.01.N Stomata IV. Water and nutrients are primarily absorbed by the roots and transported throughout the plant by various tissues in the roots, stems, and leaves. A. Roots have tiny root hairs covered with thin membranes that allow water and nutrients to enter. 1. Osmosis is the movement of water from greater concentration in the soil or media to lower concentration in the root. 2. Water enters until the concentration in the root is equal to the concentration outside the root. 3. The water entering roots also carries inorganic substances known as nutrients. B. After absorption by roots, water is passed from cell to cell until it reaches the xylem. 1. Xylem is tissue, formed as tubes, that conducts water up the stem and to the leaves. 2. The petiole of the leaf takes the water from the xylem in the stem to the leaf veins, which distribute it throughout the leaf. C. Leaves lose water by transpiration. 1. Transpiration occurs through tiny stomata on leaves. 2. Transpiration creates somewhat of an upward pull that assists the xylem in moving water and nutrients. D. Manufactured food is conducted from the leaves through the stems to the roots in phloem tissue. 1. Phloem is the tissue that conducts sugars, proteins, hormones, dissolved materials, and salts from leaves to other

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125 Teacher Directions Content Outline and/or Procedures parts of a plant. 2. The structure is observed as elongated sieve-type cells that form tube structures in stems. REVIEW/SUMMARY Focus the review and summary of the lesson on the student learning objectives. Have students explain the content associated with each objective. Use specimens of plant materials for students to use in demonstrating their knowledge of the objectives. Use student responses as the basis for reteaching. Complete Examining Plant Structures and Functions worksheet and/or have students complete questions at the end of the chapters in the text. APPLICATION

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126 Course: Agriscience Foundations I Lesson: Determining the Importance of Photosynthesis and Respiration (06.02.SM) Objectives: 1. Explain photosynthesis and its importance. 2. Write the chemical equation for photosynthesis and explain it. 3. Explain how light and dark reactions differ. 4. Define respiration and explain why it is important. 5. List four factors that affect the rate of respiration. 6. Explain the importance of transpiration to plants. Student Performance Standards Addressed: 06.02: Describe the processes of plant growth including photosynthesis, respiration, and nutrient uptake. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.02.A Energy Flow o TM: 06.02.B Photosynthesis Equation o TM: 06.02.C Two Major Phases of Photosynthesis o TM: 06.02.D Comparison of Photosynthesis and Respiration o TM: 06.02.E Factors Affecting the Rate of Respiration o TM: 06.02.F Transpiration and Gas Exchange in Leaves o TM: 06.02.G Factors Affecting the Rate of Transpiration Equipment & Supplies : Audio recorder Audio tapes Teacher Directions Content Outline and/or Procedures REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.01.SM Examining Plant Structures and Functions.

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127 Teacher Directions Content Outline and/or Procedures INTEREST APPROACH Start the lesson by shutting off the lights in the classroom. Ask the students if they could survive and continue to make energy if they were kept in the dark. Ask students what effect complete darkness would have on other mammals. Now ask the students what effect complete darkness would have on plants. OBJECTIVES 1. Explain photosynthesis and its importance. TM: 06.02.A Energy Flow TM: 06.02.C Two Major Phases of Photosynthesis TM: 06.02.B Photosynthesis Equation I. Photosynthesis is the manufacture of food by plant cells. A. Sugar is the major product of photosynthesis and provides energy for the plant. B. There are two phases to the photosynthesis process. 1. Energy gatheringPlant leaves soak up sunlight. 2. Sugar makingPlants convert energy from sunlight into stored chemical energy. a. Chemical energy rearranges carbon dioxide in the plant in the presence of chlorophyll to form sugar. b. Glucose, a simple sugar, is formed. C. Photosynthesis is the most important reaction on earth. All life forms are dependent on the reaction. 1. Occurs in the chloroplasts 2. CO2 + light + chlorophyll + H2O C6H12O6 (glucose) + H2O + O2 D. In order for photosynthesis to occur, several things must be present. 1. Chlorophyllgreen colored substance in plants. 2. LightLeaves absorb necessary energy from the suns rays or artificial light. 3. Carbon DioxideEnters the plant through structure called stomata in the leaves. Carbon dioxide is split during photosynthesis. 4. WaterWater is also split during photosynthesis.

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128 Teacher Directions Content Outline and/or Procedures 2. Write the chemical equation for photosynthesis and explain it. TM: 06.02.B Photosynthesis Equation II. Photosynthesis is a series of chemical reactions that yields sugars, water, and oxygen. A. The chemical equation of photosynthesis can be written in words: Six molecules of carbon dioxide plus twelve molecules of water in combination with a healthy plant and some form of light energy, to make one molecule of sugar plus six molecules of water and six molecules of oxygen. B. The products of photosynthesis include carbohydrates in the form of sugars and starches as well as water and oxygen. 3. Explain how light and dark reactions differ. III. Photosynthesis is a series of complex reactions that have been divided into two major phases. These two major phases have been named the light and dark reactions. A. Light Reactions 1. The light reactions are also known as light dependent reactions. Light allows energy to be released in the form of ATP which can be used by the plant in the splitting of water and the release of oxygen. 2. The pigments in chloroplasts absorb light energy to form NADPH and ATP to be used in the breakdown of CO2 in the dark reactions. B. Dark Reaction 1. Also known as light independent reactions. 2. A chemical known as RuBP (rubilose biphosphate) absorbs carbon. Carbon dioxide and RuBP join together and go through a process called the Calvin cycle. The Calvin cycle reduces carbon dioxide to manufacture carbohydrates. The NADPH and ATP synthesis from the light reactions provide the energy needed to power the Calvin cycle. 3. As a result of the Calvin cycle, one molecule of glucose is formed. 4. Define respiration and explain why it is important. TM: 06.02.D Comparison of IV. Respiration is the process by which an organism provides its cells with oxygen so energy can be released from digested food. Respiration takes place in all living cells at all times. A. Mitochondria are energy processing factories for plants.

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129 Teacher Directions Content Outline and/or Procedures Photosynthesis and Respiration Respiration takes place in the mitochondria of all cells. B. Respiration yields the opposite results as photosynthesis. The process of photosynthesis absorbs energy, consumes carbon dioxide and releases oxygen. Respiration uses energy, consumes oxygen and releases carbon dioxide. 5. List four factors that affect the rate of respiration. TM: 06.02.E Factors Affecting the Rate of Respiration V. Temperature, oxygen, soil conditions, and light can affect the rate of respiration. A. TemperatureThere is a direct relationship between respiration and temperature, as the temperature increases so does the rate of respiration. B. OxygenOxygen is required for respiration to take place. As oxygen levels decrease so does the rate of respiration. C. Soil conditionsSoil containing large quantities of water cause the rate of respiration to decrease because of the lack of oxygen. D. LightThe amount of energy produced by photosynthesis in low light conditions is reduced. Therefore the amount of energy available to conduct respiration is lower. 6. Explain the importance of transpiration in plants. TM: 06.02.F Transpiration and Gas Exchange in Leaves TM: 06.02.G Factors Affecting the Rate of Transpiration VI. Transpiration in plants is the loss of water by evaporation through structures called stomata. Stomata are pores or openings in the plant that allow for the exchange of water and other substances. Transpiration in plants is similar to perspiration in humans. A. Water molecules and transpiration together form a force that is essential for water movement through plants. 1. As water evaporates through the stomata of plant, it creates a pull that aids in the absorption of water by the roots. (An analogy of using a straw to drink will help students to visualize this process.) 2. Transpiration is a vital link in the hydrologic cycle. Ninety-nine percent of all water taken in by the plant is lost to transpiration. Therefore, transpiration contributes significantly to the generation of rainfall. B. Factors affecting the rate of transpiration include: 1. Wind speedthe relationship between wind speed and

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130 Teacher Directions Content Outline and/or Procedures transpiration is a direct relationship. 2. Temperatureas temperature increases so does the rate of transpiration because the plant uses transpiration as a mechanism to cool itself. Once again there is a direct relationship between temperature and transpiration. 3. HumidityHumidity influences the rate of transpiration because if the air is already saturated with water vapor, there will be a decrease in the rate of evaporation. 4. DroughtIf the plant is experiencing drought conditions it will close the stomata to prevent needed water from escaping. When the plants stomata are closed transpiration does not take place. REVIEW/SUMMARY Focus the review and summary of the lesson around the student learning objectives. Call on students to explain the content associated with each objective. Questions at the end of each chapter in the recommended textbooks may also be used in the review/summary. Complete the Determining the Importance of Photosynthesis and Respiration worksheet. APPLICATION

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131 Course: Agriscience Foundations I Lesson: Propagating Plants Sexually (06.03.SM) Objectives: 1. Explain sexual reproduction of plants and its importance in plant survival. 2. Explain how pollination occurs and describe the different types of pollination. 3. Explain fertilization in flowering plants. 4. Explain the structures and formation of seeds. 5. Describe the conditions for seed germination. 6. Compare and contrast indoor and outdoor growing conditions. Student Performance Standards Addressed: 06.03: Propagate plants through sexual and asexual means. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or overhead projector o TM: 06.03a.A Pollination of a Flower o TM: 06.03a.B Fertilization of a Flower o TM: 06.03a.C Parts of a Bean Seed and a Corn Seed o TM: 06.03a.D Environmental Factors Necessary for Germination Equipment & Supplies : Examples of perfect flowers (Interest Approach) Audio recorder Audio tapes Teacher Directions Content Outline and/or Procedures REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.02.SM Determining the Importance of Photosynthesis and Respiration. INTEREST APPROACH Bring a couple of samples of perfect flowers, such as from a Hibiscus or a Lily plant, to class. Use them to show the students the various parts of a flower. Dissect the flower and

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132 Teacher Directions Content Outline and/or Procedures demonstrate to students how the pollen gets from the anther to the stigma and then grows a pollen tube down through the style to fertilize the egg. Students should be able to see how the various parts of the flower interact for pollination to occur. OBJECTIVES 1. Explain sexual reproduction of plants and its importance in plant survival. I. Sexual reproduction involves flowers, fruits, and seeds. A. In sexual reproduction, sperm carried in the pollen from the male flower fuses with the egg in the female part of the flower. Both contribute to the genetic makeup of the new plant. B. Each time sexual reproduction occurs, there is a recombining of genetic material. As a result, some changes will occur. Some may be beneficial and some may not. As conditions of the environment change over time, the beneficial changes in plant genetics will allow the plant to survive. As plants continue to reproduce, they pass genes onto their offspring, which enables them to survive. 2. Explain how pollination occurs and describe the different types of pollination. TM: 06.03a.A Pollination of a Flower II. Pollination is the transfer of pollen from the male to the female part of a plant. A. Pollination occurs in many different ways: 1. Birds, insects, bats, and other animals are attracted to colorful, scented flowers. As they visit various flowers for food, they unintentionally pick up pollen and carry it from flower to flower. 2. Wind moves pollen from one flower to another. Plants that rely on wind generally do not produce colorful flowers with scents or nectar. B. Pollination of plants may occur in one of two ways: 1. Self-pollination occurs when pollen from a plant pollinates a flower on the same plant. 2. Cross-pollination occurs when pollen from a plant pollinates a flower on a different plant. C. Once pollen lands on the stigma, it grows a pollen tube down the style to the ovary. The cell within the grain of pollen divides to form two sperm nuclei, which travel down

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133 Teacher Directions Content Outline and/or Procedures the pollen tube to the embryo sac, fertilizing the egg. 3. Explain fertilization in flowering plants. TM: 06.03a.B Fertilization of a Flower III. Fertilization is necessary in flowering plants in order for the seed to develop. A. Fertilization in flowering plants is different from fertilization in any other living organism. In plants, both sperm nuclei in the pollen grain are involved in fertilization, resulting in a double fertilization. 1. The first fertilization occurs when one sperm fuses with the egg, resulting in a zygote. The resulting seed contains genetic information from both the male and female part of the flower. 2. The second fertilization occurs when the second sperm nucleus fuses with the two nuclei in the embryo sac. This will develop into the endosperm. The ovule of the flower will become the seed. B. When fertilization occurs and the parents are genetically different, the resulting offspring is said to be a hybrid. The advantage of hybrids is that the best traits of each parent, such as more vigorous growth, insect and disease resistance, or uniformity, may be expressed in the offspring. C. Genetic information is stored in every cell of a plant in long molecular chains made of Deoxyribonucleic acid (DNA). Segments of DNA, called genes, establish the code for life processes and the appearance of a plant. The genes are arranged in a set of chromosomes. Normal cells contain a double set of chromosomes and are said to be diploid. Reproductive cells, sperm and egg cells, have a single set of chromosomes and are said to be haploid. When fertilization occurs, the single sets of chromosomes are combined into the double set, one from each parent, resulting in traits from each parent being passed on to the offspring. 4. Explain the structures and formation of seeds. TM: 06.03a.C Parts of a Bean Seed and a Corn Seed. IV. The function of the seed is to grow and develop into a mature plant that will produce more seeds. A. Seeds of flowering plants have several parts. 1. The seed coat is a protective shell surrounding the embryo and endosperm. It protects the seed from drying and from physical injury. The seed coat helps in determining when conditions for germination or the beginning of growth are

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134 Teacher Directions Content Outline and/or Procedures right. 2. The embryo is a little plant that eventually grows and develops into the mature plant. It remains dormant within the seed. It has a stem, root, and one or two seed leaves called cotyledons. Monocot embryos have one seed leaf and dicot embryos have two seed leaves. 3. The endosperm is the food storage tissue in the seed, particularly in monocots. Dicots store their food in the two cotyledons. The food storage is necessary for the young seedling until it is able to manufacture its own food. B. After fertilization, the ovary wall enlarges and forms the fruit. The fruit may be fleshy or dry. 1. Fleshy fruit prevents the seeds from drying until they are mature. They also serve to help disperse the seeds. Animals are attracted to fruit, eat it with the seeds, and disperse or disseminate the seeds somewhere away from the parent plant. Examples of fleshy fruit include tomatoes, apples, pears, etc. 2. Dry fruit is found on plants such as the dandelion and maple trees. It does not depend on animals for dissemination, but may depend on wind or other methods of dissemination. 5. Describe the conditions for seed germination. TM: 06.03a.D Environmental Factors Necessary for Germination V. Seeds are designed to wait for favorable conditions to begin growth. They may lay dormant for many years before conditions allow them to begin to grow. A. Several environmental factors play key roles in seed germination. 1. Moisture or water is necessary for germination. 2. Air, particularly oxygen, is required for germination. 3. Warm temperatures, between 40 and 104 degrees F, are necessary for germination. 4. Some plants require light or total darkness for germination. B. Stratification is when the seed must go through a period of cold temperatures before it will germinate. C. Scarification is the breaking down of the seed coat. Some

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135 Teacher Directions Content Outline and/or Procedures seeds have such a hard, thick seed coat that they prevent the absorption of water to enable germination to occur. D. The germination process begins with the absorption of water. The seed swells and the embryo changes from a dormant state to an actively growing plant. The embryo draws energy from starches stored in the endosperm or cotyledons. The embryos root emerges from the seed and develops into the primary root. Then, the stem of the embryo sprouts upward. E. The quality of seed used is very important in production agriculture. Viable, or live, seed is important to ensure a high percentage of seed germination. Seed companies test seed to determine its germination percentage, which must be printed on the seed bag. Proper humidity and temperature during storage of the seeds help maintain seed viability. 5. High salt concentrations in the soil can have adverse effects on plant growth. A. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. B. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, and developing simple methods of measuring soil salinity concentrations in the soil. C. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can lead to salt buildup in the growing medium and eventual death of the plant. 6. Compare and contrast indoor and outdoor growing conditions. VI. The grower has control over the quality and condition of seed, planting procedure, and weed competition, environmental conditions cannot be controlled in outdoor

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136 Teacher Directions Content Outline and/or Procedures settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and/or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. B. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. REVIEW/SUMMARY Use the student learning objectives to summarize the lesson. Have students explain the content associated with each objective. Student responses can be used in determining which objectives need to be reviewed or taught from a different perspective. Questions at the end of chapters of textbooks covering this material may also be used in the review/summary. Complete Propagating Plants Sexually Worksheet. APPLICATION

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137 Prescriptive Laboratory Approach Course: Agriscience Foundations I Lesson: Scientific Method (06.00.PL) Objectives: 1. Identify the steps involved in the scientific method of investigation. 2. Define common terms used in agriscience research. 3. Properly report scientific findings. Student Performance Standards Addressed: 04.01 04.05 04.06 Equipment, Supplies, References, and Other Resources: References : Cooper, E. L. & Burton, L. D. (2004) Agriscience: Fundamentals and applications (3 rd Edition). Albany, NY: Delmar. (Unit 1). Osborne, E. W. (1994). Biological science applications in agriculture. Danville, IL: Interstate Publishers, Inc. (Chapter 1). Handouts : The Experimentation Process handout LS: 06.00.PL Determining Mass Student Handout Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.00.A The Scientific Method o TM: 06.00.B Agriscience Terms o TM: 06.00.C Guidelines for Constructing Charts and Graphs Equipment & Supplies : See materials list on lab sheet Audio recorder Audio tapes Teacher Directions Content Outline and/or Procedures REVIEW None new unit INTEREST APPROACH Push record on audio recorder Ask the students to explain the process by which scientists conduct investigations. Ask them to create a step by step procedure. Then ask for volunteers to share their procedure with the rest of the class. Compare student examples with the procedure suggested in the lesson.

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138 Teacher Directions Content Outline and/or Procedures OBJECTIVES 1. Identify the steps involved in the scientific method of investigation. TM: 06.00.A The Scientific Method A. The scientific method has five steps. 1. Define the problemusually stated as a question. a. What do you want to know? 2. Gather data (facts and information) about the problem. a. Summarize past experiences. b. Review other research results. 3. Suggest possible answers or solutions. a. A hypothesis is a prediction of the results of an experiment. b. Write the hypothesis before beginning the experiment. 4. Test the hypothesis. a. Conduct an experiment to test the hypothesis. b. Summarize the data collected in organized charts or tables. 5. Evaluate the results. a. Examine the findings of the experiment. b. Draw conclusions or judgments made on the basis of the findings. 2. Define common terms used in agriscience research. TM: 06.00.B Agriscience Terms B. Key terms used in agriscience experiments 1. Independent variable : Will affect another variable a. Known as treatment 2. Dependent variable : Observed variable; expected to change due to independent variable 3. Replication exact duplication a. Allows for validation 3. Properly report scientific findings TM: 06.00.C Guidelines for C. Data may be summarized and reported in many different ways. 1. Descriptive statistics are one common method. Common descriptive statistics are: a. Means which are averages b. Frequency distributions which are simply counts of how many times something occurred. c. Percentages

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139 Teacher Directions Content Outline and/or Procedures Constructing Charts and Graphs 2. Data can be visually summarized using charts and graphs. When constructing a graph, there are certain guidelines to follow: a. The independent variable (X) is reported on the horizontal axis (x-axis). b. The dependent variable (Y) is reported on the vertical axis (y-axis). c. Be sure to label the axis and title the graph. REVIEW/SUMMARY Use questioning to determine if students understand the content material of this lesson APPLICATION Complete LS 06.00.PL Determining Mass

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140 LS: 06.00.PL Teacher Instructions Determining Mass Interest Approach: (Present as follows.) Ask students, What is mass? Select a few students to offer their definition. Then hold up a piece of bubble gum and ask the students, What will happen to the mass (weight) of this piece of bubble gum when I chew it? Research Problem: (Discuss.) What effect does chewing have on the mass of bubble gum? Purpose: (Present to class and discuss.) The purpose of this experiment is to observe the effect chewing has on the mass of bubble gum. Also, this experiment will familiarize students with the scientific method. Materials: (Give to students.) Balances or scales Bubble gum Graph paper Procedures: (Give a copy to students and have them conduct the experiment.) (2-4 students per group) 1. Weigh one piece of bubble gum. Record the mass. 2. Develop a hypothesis on the effect chewing will have on the mass of the bubble gum. Record your hypothesis. 3. Chew the bubble gum for 30 seconds. Using the wrapper as a weigh paper, determine the mass of the bubble gum. 4. Repeat step #3 until bubble gum has been chewed for 5 minutes. 5. Graph the results of your findings. (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 6. Evaluate hypothesis Data Summary: (Give sample data table to students and lead a discussion on how to summarize the data from other parts of the experiment.) Observations should be taken of the experiment at regular intervals. Have students complete a simple data summary table stating their observations.

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141 Sample Data Summary Table Time 0:00 0:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00 Mass Conclusions: (Lead a discussion of these and other conclusions.) 1. Mass of the bubble gum decreased as it was chewed. 2. The decline in mass was greatest in the beginning. As time passed, the rate of decline slowed. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to answer the research question?) 3. What would you do differently in conducting this experiment a second time? 4. Why did the rate at which the mass changed slow down? Further Investigation: (Lead a discussion of these and other ideas.) 1 Compare different types of gum. 2. Instead of using time as the dependent variable, count the number of chews. Questions: (Lead a discussion of these and other questions.) What was your hypothesis? Was it correct? What is the dependent variable in this experiment? Answer: Time What is the independent variable in this experiment? Answer: Mass

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142 LS: 06.00.PL Student Handout Determining Mass Purpose: The purpose of this experiment is to observe the effect chewing has on the mass of bubble gum. Also, this experiment will familiarize students with the scientific method. Research Problem: (Discuss.) What effect does chewing have on the mass of bubble gum? Your hypothesis is: Materials: Balances or scales Bubble gum Graph paper Procedures: 1. Weigh one piece of bubble gum. Record the mass. 2. Develop a hypothesis on the effect chewing will have on the mass of the bubble gum. Record your hypothesis. 3. Chew the bubble gum for 30 seconds. Using the wrapper as a weigh paper, determine the mass of the bubble gum. 4. Repeat step #3 until bubble gum has been chewed for 5 minutes. 5. Graph the results of your findings. 6. Evaluate hypothesis Data Summary: Observations should be taken of the experiment at regular intervals. Complete the following data summary table stating your observations. Data Summary Table Time 0:00 0:30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00 Mass

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143 Questions: What was your hypothesis? Was it correct? What is the dependent variable in this experiment? What is the independent variable in this experiment?

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144 Course: Agriscience Foundations I Lesson: Examining Plant Structures and Functions (06.01.PL) Objectives: 1. Describe the cellular structure of plants. 2. Identify the major parts of plants and explain their functions. 3. Distinguish between plants based on seed cotyledons. 4. Explain the absorption and transport systems of plants. Student Performance Standards Addressed: 06.01: Describe the structure functions of plant parts including roots, stems, leaves, and flowers. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Handouts : Lab Sheet 06.01.PL Osmotic Turgescence (Pressure) Student Handout Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.01.A Major Parts of a Plant Cell o TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers o TM: 06.01.C Parts of a Typical Stem o TM: 06.01.E Specialized Stems o TM: 06.01.F Kinds of Roots o TM: 06.01.G Leaf types o TM: 06.01.H Comparison of Monocot and Dicot Seed o TM: 06.01.K Arrangement of Tissues in Stems o TM: 06.01.L Roots o TM: 06.01.M Absorption o TM: 06.01.N Stomata Equipment & Supplies : Plant specimen (Interest Approach) See materials list on lab sheet Audio recorder Audio tapes

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145 Teacher Directions Content Outline and/or Procedures REVIEW None new unit INTEREST APPROACH Push record on audio recorder Bring a small plant specimen (about 18 inches long) that has been pulled up so that leaves, stems, and roots are obvious. A specimen with flowers and/or fruit is preferred. Ask students to name the different parts of the specimen. As they do, have them describe the function of the part and how it is useful to humans. Move from the interest approach into the objectives and anticipated problems for the lesson. OBJECTIVES 1. Describe the cellular structure of plants. TM: 06.01. A Major Parts of a Plant Cell I. Cells are the structural basis of all living organisms. A. A cell is a tiny structure that forms the basic building blocks of plants. 1. All organisms are made of one or more cells. 2. Protoplasm in cells carries out life processes. B. Plants are multi-cellular organisms, meaning that they have many cells. 1. Some cells have specific functions. 2. Cell specialization is the presence of cells that perform unique activities for a plant. (Flowers, leaves, roots, and stems are made of specialized cells.) C. Cells are formed into groups that work together. 1. Tissue is formed by groups of cells that are alike in activity and structure. 2. An organ is formed by tissues that work together to perform specific functions. 3. An organ system is a group of organs that works together to perform a function. D. Cell structure is the organization of the material that forms a cell. 1. Plant cells have three major parts: wall, nucleus, and

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146 Teacher Directions Content Outline and/or Procedures cytoplasm. 2. The cell wall surrounds the cell and controls the movement of materials into and out of the cell. 3. The nucleus is near the center of a cell and contains protoplasm, chromosomes, and other structures that control cell activity. 4. The cytoplasm is a thick solution inside the cell wall surrounding the nucleus. 5. Plant cells have many additional parts, including: chloroplasts, nucleolus, vacuole, mitochondria, and golgi body. 2. Identify the major parts of plants and explain their functions. TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers TM: 06.01.C Parts of a Typical Stem TM: 06.01.E Specialized Stems II. Plants are comprised of vegetative and reproductive parts. A. The major vegetative parts of plants are stems, leaves, and roots. 1. A stem is the central axis that supports the leaves, connects them with the roots, and transports water and other materials between the leaves and roots. Stems vary widely in appearance based on the species of plant. Stems may be vertical or horizontal and modified for climbing and to store water and food. Several specialized kinds of stems are important: a. RhizomeA rhizome is an underground stem that grows horizontally. It may grow adventitious roots and stems to develop as a separate plant. Examples include iris and wild ginger. b. TuberA tuber is an enlarged part of a stem that grows underground. A tuber can develop into a separate plant. Examples include potatoes and yams. c. TendrilA tendril is a threadlike leafless growth on a stem that attaches itself around other stems and objects. Tendrils typically grow in a spiral shape. After attaching itself, it holds the stem in position. Vines and climbing plants often have tendrils. Examples include sweet peas and cucumbers.

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147 Teacher Directions Content Outline and/or Procedures TM: 06.01.F Kinds of Roots TM: 06.01.G Leaf types TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers d. StolonA stolon is an above ground stem that grows horizontally and propagates new plants. Strawberries are well known as examples of plants that multiply using stolons. e. BulbA bulb is an underground food-storage organ consisting of flattened, fleshy stem-like leaves with roots on the lower side. Examples of bulbs are onions and daffodils. f. CormA corm is a food storage structure at the end of a stem that grows underground. It is an enlarged or swollen stem base. Examples include gladiolus and crocus. g. CladophyllA cladophyll is a leaflike branch that resembles a leaf. It is also called a cladode. A cladophyll functions much like a leaf. 2. A root is the part of a plant that grows in the soil or other media. Roots anchor plants, absorb water and minerals, and store food. The root system structure varies widely depending on the species of plant. Overall, roots can be classified as two major types: a. FibrousA fibrous root system is made of many small roots and spread throughout the soil. b. TaprootA taproot system is made of one primary root with a number of small secondary roots. 3. A leaf is typically a large, flat, green organ attached to the stem. Leaves carry out photosynthesis, transpiration, and may store food. Shape, arrangement, and other features vary widely with the species of plant. There are two major kinds of leaves and three major types of arrangements: a. SimpleA simple leaf has only one blade. b. CompoundA compound leaf is divided into two or more leaflets c. Leaf attachment also varies. This refers to the spacing and arrangement of leaves on the stem of a plant. The major kinds of attachment

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148 Teacher Directions Content Outline and/or Procedures are: (1) AlternateAlternate leaf arrangement is one leaf at each node on a stem. (2) OppositeOpposite leaf arrangement is two leaves are attached at nodes opposite each other. (3) WhorledWhorled leaf arrangement is three or more leaves are at each node. B. The major reproductive parts of plants are flowers, seed, and fruit. 1. A flower is a part containing the reproductive organs. The types of flowers vary considerably. In general, flowers produce pollen and ovules. Fertilization occurs when a pollen cell unites with an ovule. 2. Seed are formed by fertilized ovules and contain new plant life. 3. Fruit are the ovaries which develop to protect and nourish the developing seed. The kinds and nature of fruit vary widely. 3. Distinguish between plants based on seed cotyledons. TM: 06.01.H Comparison of Monocot and Dicot Seed III. A cotyledon is the fleshy structure within a seed that contains food for a developing embryo. A. Depending on the plant species, a seed may have one or two cotyledons. B. A plant species producing seed with one cotyledon is a monocotyledon, or monocot. 1. All grasses are monocots. Corn, wheat, oats, Bermuda grass, and sugarcane are examples of monocots. 2. Monocot plants have long, narrow leaves with parallel veins. All leaves branch from the main stem. 3. Stems are non-woody and tend to have a large area of pith in the center. C. A plant species producing seed with two cotyledons is a

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149 Teacher Directions Content Outline and/or Procedures dicotyledon, or dicot. 1. All plants other than grasses are dicots. Soybeans, trees, lettuce, sunflowers, and petunias are examples of dicots. 2. Dicot plants have broad leaves with a net-type of veins. 3. Stems are often long and branching. They may be woody or non-woody, depending on the plant species. 4. Explain the absorption and transport systems of plants. TM: 06.01.K Arrangement of Tissues in Stems TM: 06.01.L Roots TM: 06.01.M Absorption TM: 06.01.N Stomata IV. Water and nutrients are primarily absorbed by the roots and transported throughout the plant by various tissues in the roots, stems, and leaves. A. Roots have tiny root hairs covered with thin membranes that allow water and nutrients to enter. 1. Osmosis is the movement of water from greater concentration in the soil or media to lower concentration in the root. 2. Water enters until the concentration in the root is equal to the concentration outside the root. 3. The water entering roots also carries inorganic substances known as nutrients. B. After absorption by roots, water is passed from cell to cell until it reaches the xylem. 1. Xylem is tissue, formed as tubes, that conducts water up the stem and to the leaves. 2. The petiole of the leaf takes the water from the xylem in the stem to the leaf veins, which distribute it throughout the leaf. C. Leaves lose water by transpiration. 1. Transpiration occurs through tiny stomata on leaves. 2. Transpiration creates somewhat of an upward pull that assists the xylem in moving water and nutrients. D. Manufactured food is conducted from the leaves through the stems to the roots in phloem tissue.

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150 Teacher Directions Content Outline and/or Procedures 1. Phloem is the tissue that conducts sugars, proteins, hormones, dissolved materials, and salts from leaves to other parts of a plant. 2. The structure is observed as elongated sieve-type cells that form tube structures in stems. REVIEW/SUMMARY Focus the review and summary of the lesson on the student learning objectives. Have students explain the content associated with each objective. Use specimens of plant materials for students to use in demonstrating their knowledge of the objectives. Use student responses as the basis for reteaching. Complete Examining Plant Structures and Functions worksheet and/or have students complete questions at the end of the chapters in the text. APPLICATION Complete LS: 06.01.PL Osmotic Turgescence (Pressure)

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151 LS: 06.01.PL Teacher Instructions Osmotic Turgescence (Pressure) Interest Approach: (Present as follows.) Bring to class two sets of bean seeds. One of the sets should be soaked in water for approximately four hours prior to class. As the students to compare the two sets of seeds. Ask them why the seeds that had been soaked are larger. Agriscience Applications: (Discuss.) When cells in growing tissues split and enlarge as water and nutrients are absorbed and used to make new cellular materials, a tremendous force is produced. This force is called osmotic turgescence. The strength of the force depends upon characteristics of the seed. Hydraulic pressure causes a stretching effect on the cell walls, making cell enlargement (growth) possible. Plant cells are osmotic systems. The concentration of water is less inside the cell than outside. This osmotic process generates the cells internal hydraulic pressure. As water enters the cell, its volume and hydraulic pressure increase. Research Problem: (Present and discuss.) How much pressure is exerted by a seed as it takes up water for germination? Purpose: (Present to class and discuss.) The purpose of this experiment is to observe the pressure exerted by germinating seeds. Materials: (Give to students.) lima bean seeds (or other large beans) dry, clean sand pint jar with lid masking tape box or pan pen or pencil Procedures: (Give a copy to students and have them conduct the experiment.) (4 students per group) Place an equal amount of beans and sand in a jar. Shake the jar to mix the beans and sand completely. Push the sand in tightly. Fill the jar to the top with sand. Wet the sand, but do not put enough water into the jar to flood it. Screw the lid on tightly Label each jar by putting your name on a piece of masking tape on the lid of the jar.

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152 Place the jar on a large pan or box in an area away from students. (This contains the mess of broken jars and aids in clean up afterwards.) Observe what happens to the jar after a few hours. Record observations. Data Summary: (Give sample data table to students and lead a discussion on how to summarize the data from other parts of the experiment.) Observations should be taken of the experiment at regular intervals. Have students complete a simple data summary table stating their observations. Be sure student observations are written in complete sentences and with good sentence structure. Sample Data Summary Table Time Observation Conclusions: (Lead a discussion of these and other conclusions.) 1. Expanding seeds create enough pressure to break glass jars. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to observe the pressure exerted by germinating seeds?) 3. What would you do differently in conducting this experiment a second time? 4. Why did some jars break more quickly than others? 5. Why did some jars not break at all? 6. What was the purpose of the sand in the experiment? Further Investigation: (Lead a discussion of these and other ideas.) 1 Compare different types of seeds. 2 Vary the amount of sand and seed placed in each jar. 3 Vary the temperature or light received by the jar to see if they have an effect on water uptake by the seed.

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153 LS: 06.01.PL Student Handout Osmotic Turgescence (Pressure) Purpose: The purpose of this experiment is to observe the pressure exerted by germinating seeds. Research Problem: How much pressure is exerted by a seed as it takes up water for germination? Your hypothesis is: Materials: lima bean seeds (or other large beans) dry, clean sand pint jar with lid masking tape box or pan pen or pencil Procedures: Place an equal amount of beans and sand in a jar. Shake the jar to mix the beans and sand completely. Push the sand in tightly. Fill the jar to the top with sand. Wet the sand, but do not put enough water into the jar to flood it. Screw the lid on tightly Label each jar by putting your name on a piece of masking tape on the lid of the jar. Place the jar on a large pan or box. Observe what happens to the jar after a few hours. Record your observations. Agriscience Applications: When cells in growing tissues split and enlarge as water and nutrients are absorbed and used to make new cellular materials, a tremendous force is produced. This force is called osmotic turgescence. The strength of the force depends upon characteristics of the seed. Hydraulic pressure causes a stretching effect on the cell walls, making cell enlargement (growth) possible. Plant cells are osmotic systems. The concentration of water is less inside the cell than outside. This osmotic process generates the cells internal hydraulic pressure. As water enters the cell, its volume and hydraulic pressure increase.

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154 Data Summary: Data Summary Table Time Observation

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155 Course: Agriscience Foundations I Lesson: Determining the Importance of Photosynthesis and Respiration (06.02.PL) Objectives: 1. Explain photosynthesis and its importance. 2. Write the chemical equation for photosynthesis and explain it. 3. Explain how light and dark reactions differ. 4. Define respiration and explain why it is important. 5. List four factors that affect the rate of respiration. 6. Explain the importance of transpiration to plants. Student Performance Standards Addressed: 06.02: Describe the processes of plant growth including photosynthesis, respiration, and nutrient uptake. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Handouts : LS: 06.02.PL Transpiration in Plants Student Handout Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or Overhead projector o TM: 06.02.A Energy Flow o TM: 06.02.B Photosynthesis Equation o TM: 06.02.C Two Major Phases of Photosynthesis o TM: 06.02.D Comparison of Photosynthesis and Respiration o TM: 06.02.E Factors Affecting the Rate of Respiration o TM: 06.02.F Transpiration and Gas Exchange in Leaves o TM: 06.02.G Factors Affecting the Rate of Transpiration Equipment & Supplies : See materials list on lab sheet Audio recorder Audio tapes

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156 Teacher Directions Content Outline and/or Procedures REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.01.PL Examining Plant Structures and Functions. INTEREST APPROACH Start the lesson by shutting off the lights in the classroom. Ask the students if they could survive and continue to make energy if they were kept in the dark. Ask students what effect complete darkness would have on other mammals. Now ask the students what effect complete darkness would have on plants. OBJECTIVES 1. Explain photosynthesis and its importance. TM: 06.02.A Energy Flow TM: 06.02.C Two Major Phases of Photosynthesis TM: 06.02.B Photosynthesis Equation I. Photosynthesis is the manufacture of food by plant cells. A. Sugar is the major product of photosynthesis and provides energy for the plant. B. There are two phases to the photosynthesis process. 1. Energy gatheringPlant leaves soak up sunlight. 2. Sugar makingPlants convert energy from sunlight into stored chemical energy. a. Chemical energy rearranges carbon dioxide in the plant in the presence of chlorophyll to form sugar. b. Glucose, a simple sugar, is formed. C. Photosynthesis is the most important reaction on earth. All life forms are dependent on the reaction. 1. Occurs in the chloroplasts 2. CO2 + light + chlorophyll + H2O C6H12O6 (glucose) + H2O + O2 D. In order for photosynthesis to occur, several things must be present. 1. Chlorophyllgreen colored substance in plants. 2. LightLeaves absorb necessary energy from the suns rays or artificial light.

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157 Teacher Directions Content Outline and/or Procedures 3. Carbon DioxideEnters the plant through structure called stomata in the leaves. Carbon dioxide is split during photosynthesis. 4. WaterWater is also split during photosynthesis. 2. Write the chemical equation for photosynthesis and explain it. TM: 06.02.B Photosynthesis Equation II. Photosynthesis is a series of chemical reactions that yields sugars, water, and oxygen. A. The chemical equation of photosynthesis can be written in words: Six molecules of carbon dioxide plus twelve molecules of water in combination with a healthy plant and some form of light energy, to make one molecule of sugar plus six molecules of water and six molecules of oxygen. B. The products of photosynthesis include carbohydrates in the form of sugars and starches as well as water and oxygen. 3. Explain how light and dark reactions differ. III. Photosynthesis is a series of complex reactions that have been divided into two major phases. These two major phases have been named the light and dark reactions. A. Light Reactions 1. The light reactions are also known as light dependent reactions. Light allows energy to be released in the form of ATP which can be used by the plant in the splitting of water and the release of oxygen. 2. The pigments in chloroplasts absorb light energy to form NADPH and ATP to be used in the breakdown of CO2 in the dark reactions. B. Dark Reaction 1. Also known as light independent reactions. 2. A chemical known as RuBP (rubilose biphosphate) absorbs carbon. Carbon dioxide and RuBP join together and go through a process called the Calvin cycle. The Calvin cycle reduces carbon dioxide to manufacture carbohydrates. The NADPH and ATP synthesis from the light reactions provide the energy needed to power the Calvin cycle. 3. As a result of the Calvin cycle, one molecule of glucose is formed. 4. Define respiration and IV. Respiration is the process by which an organism

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158 Teacher Directions Content Outline and/or Procedures explain why it is important. TM: 06.02.D Comparison of Photosynthesis and Respiration provides its cells with oxygen so energy can be released from digested food. Respiration takes place in all living cells at all times. A. Mitochondria are energy processing factories for plants. Respiration takes place in the mitochondria of all cells. B. Respiration yields the opposite results as photosynthesis. The process of photosynthesis absorbs energy, consumes carbon dioxide and releases oxygen. Respiration uses energy, consumes oxygen and releases carbon dioxide. 5. List four factors that affect the rate of respiration. TM: 06.02.E Factors Affecting the Rate of Respiration V. Temperature, oxygen, soil conditions, and light can affect the rate of respiration. A. TemperatureThere is a direct relationship between respiration and temperature, as the temperature increases so does the rate of respiration. B. OxygenOxygen is required for respiration to take place. As oxygen levels decrease so does the rate of respiration. C. Soil conditionsSoil containing large quantities of water cause the rate of respiration to decrease because of the lack of oxygen. D. LightThe amount of energy produced by photosynthesis in low light conditions is reduced. Therefore the amount of energy available to conduct respiration is lower. 6. Explain the importance of transpiration in plants. TM: 06.02.F Transpiration and Gas Exchange in Leaves VI. Transpiration in plants is the loss of water by evaporation through structures called stomata. Stomata are pores or openings in the plant that allow for the exchange of water and other substances. Transpiration in plants is similar to perspiration in humans. A. Water molecules and transpiration together form a force that is essential for water movement through plants. 1. As water evaporates through the stomata of plant, it creates a pull that aids in the absorption of water by the roots. (An analogy of using a straw to drink will help students to visualize this process.) 2. Transpiration is a vital link in the hydrologic cycle. Ninety-nine percent of all water taken in by the plant is lost to transpiration. Therefore, transpiration contributes

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159 Teacher Directions Content Outline and/or Procedures TM: 06.02.G Factors Affecting the Rate of Transpiration significantly to the generation of rainfall. B. Factors affecting the rate of transpiration include: 1. Wind speedthe relationship between wind speed and transpiration is a direct relationship. 2. Temperatureas temperature increases so does the rate of transpiration because the plant uses transpiration as a mechanism to cool itself. Once again there is a direct relationship between temperature and transpiration. 3. HumidityHumidity influences the rate of transpiration because if the air is already saturated with water vapor, there will be a decrease in the rate of evaporation. 4. DroughtIf the plant is experiencing drought conditions it will close the stomata to prevent needed water from escaping. When the plants stomata are closed transpiration does not take place. REVIEW/SUMMARY Focus the review and summary of the lesson around the student learning objectives. Call on students to explain the content associated with each objective. Questions at the end of each chapter in the recommended textbooks may also be used in the review/summary. Complete the Determining the Importance of Photosynthesis and Respiration worksheet. APPLICATION Complete LS: 06.02.PL Transpiration in Plants

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160 LS: 06.02.PL Teacher Instructions Transpiration in Plants Interest Approach: (Present as follows) Ask three to five students to volunteer participate in a race. Give each volunteer a penny, a pipette, and cup of water. The rules of the competition are simple, the person who can put the largest numbers of water drops on the top of the penny without getting the table wet wins. You may also ask for another set of students to volunteer to help count the number of drops on each students penny. After the race is over, ask the competitors to describe to the rest of the class what happened. Why were you able to get so many drops on the penny? Describe the properties of adhesion and cohesion. Relate to transpiration in plants. Agriscience Applications: (Discuss) Transpiration is the loss of water through plant leaves. Over 90% of all water absorbed by the plant is lost through this process. This water loss occurs through the stomata, which are located on the underside of plant leaves. Some plants also have stomata on the upper side of the leaves. The stomata are pores that open and close under certain conditions. In addition to allowing water vapor to escape, the stomata also allow the inward movement of atmospheric carbon dioxide which is used in photosynthesis. Osmosis and diffusion are the primary means by which plants absorb water from the soil and release water through transpiration. Diffusion is the movement of molecules (water) from a region of higher concentration to a region of lower concentration. Transpiration water losses occur by diffusion. Osmosis is the diffusion of water through a differentially permeable membrane. Water enters the cell by osmosis then travels across several membranes until it moves into the xylem. It is then transported to the leaves where much of the water is diffused through the stomata. The upward movement of water from the roots to the leaves is known as the transpiration stream. As water is lost from the outer tissues of the leaf, water moves in from interior tissue. Differences in osmotic pressure between cell layers causes this suction of water from the roots to the leaves. This process is facilitated by the cohesion properties of water. Cohesion is the attraction between like molecules (water to water). Adhesion is the attraction between unlike molecules (water to plant tissue). Light, carbon dioxide concentrations, and water content in plant tissue affect the stomata. Air movement and humidity affect the opening and closing the stomata. Changes in turgor pressure of the guard cells cause the stomatal pores to open and close. When the stomata are closed, water loss is reduced. However, if the stomata are closed, carbon dioxide cannot enter the plant. Thus prohibiting photosynthesis from occurring. Maintaining adequate soil moisture is a critical management practice in plant growth for both indoor and outdoor growing conditions. For greenhouse crops, watering is probably the most time-consuming task required in growing a given crop. Fortunately, the high labor costs of maintaining proper moisture levels is somewhat offset by the relatively low cost of water as an input for greenhouse crops.

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161 In outdoor growing conditions, including vegetables, turf, and field crops, soil moisture fluctuates much more and reaches more extreme levels than in more controlled, indoor environments. Thus, maintaining adequate soil moisture levels in outdoor conditions is much more of a challenge, due to weather factors beyond the grower's control. Soil moisture levels are increased either by natural means (rainfall) or artificially via irrigation. Moisture losses occur primarily through the evaporation of water from the upper soil layers through the loss of water through leaf surfaces and other plant parts (transpiration). The rate of water loss as a result of transpiration is primarily dependent upon weather (i.e., temperature and humidity). Thus, growers must seasonally adjust their crop schedules according to the water intake and loss responses of the plants being grown. Research Problems: (Present and discuss) 1. What effect does leaf size and number have on plant transpiration rate? 2. What effect does air movement have on plant transpiration rate? Purpose: (Present to class and discuss) The purpose of this experiment is to observe the general rate of transpiration in plants and to examine the effects of wind on transpiration rate. Through this lab, students will be able to: 1. describe the biological process of transpiration in plants; 2. identify the factors that affect transpiration and explain why and how these effects are realized; 3. measure transpiration rates in given test plants; and 4. explain the relationship between transpiration and soil moisture management practices on plant growth. Materials: (Give to students) Four 50-milliliter graduated cylinders Modeling clay Cooking oil Cuttings from a large-leafed, herbaceous plant Water Electric fan Graph paper Procedures: (Give a copy to students and have them conduct the experiment.) (4 students per group)

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162 1. Take four stem cuttings (8 to 10 inches long) from stock plants. Choose stem cuttings with leaves of relatively equal size. Remove all but one leaf from two of the cuttings. Leave three or four leaves on each of the other two cuttings. 2. Add water to the four graduated cylinders. 3. Place the stem of the cuttings so they extend well below the water line in the graduated cylinders. 4. Pour 2 milliliters of cooking oil on top of the water in the graduated cylinder to prevent evaporation losses. 5. Gently pack modeling clay around the stem at the cylinder opening to provide support for the plant. Be careful not to crush the stem. Try to establish initial water line near 40 milliliters. 6. Record the water level in each cylinder. 7. Place all four cylinders under the same environmental conditions (temperature, light, etc.) with one exception. Two of the cylinders (one with a single leaf and one with multiple leaves) should be placed in front of a low-speed fan. 8. Record the water level in each cylinder on a regular basis. 9. Summarize the data. Graph the results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Data Summary: (Give sample data table to students and lead a discussion on how to summarize the data obtained from other parts of the experiment.) Observations should be taken of the experiment at regular intervals. Have students complete the simple data summary table. Students should graph the water loss the occurred during the time of the experiment. End Day 1 Beginning Day 2 End of Day 2 Treatment Initial Reading Reading Net Change Reading Net Change Reading Net Change 1 leaf, no fan 3-4 leaves, no fan 1 leaf, fan 3-4 leaves, fan Conclusions: (Lead a discussion of these and other conclusions.) 1. Moisture is lost through the leaves. 2. The greater the number of leaves (leaf surface area), the greater the loss from transpiration. 3. Increased airflow (up to a certain speed) will increase the rate of transpiration.

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163 Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1. What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures allow you to answer the research question? 3. What would you do differently in conducting this experiment a second time? 4. What effect would transpiration have on the way you would manage a greenhouse? 5. What plants would be more susceptible to greater losses of moisture due to transpiration? 6. Why were herbaceous plants selected for this experiment? 7. Why does air movement tend to increase the rate of transpiration? 8. What would happen if transpiration rate exceeded the rate at which the plant could replenish the water in its tissues? 9. At what point does an increase in air speed decrease transpiration? Why? 10. What is the relationship between rate of transpiration and leaf surface area? 11. What causes water to be pulled upward into the leaf stems? Further Investigation: (Lead a discussion of these and other ideas.) 1. Examine the effects of additional environmental factors such as light intensity, temperature, and humidity on the rate of transpiration in plants. 2. Examine the rate of transpiration in plants that are growing under various degrees of soil moisture.

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164 LS: 06.02.PL Student Handout Transpiration in Plants Purpose of this Lab: The purpose of this experiment is to observe the general rate of transpiration in plants and to examine the effects of wind on transpiration rate. Through this lab, students will be able to: 1. describe the biological process of transpiration in plants; 2. identify the factors that affect transpiration and explain why and how these effects are realized; 3. measure transpiration rates in given test plants; and 4. explain the relationship between transpiration and soil moisture management practices on plant growth. Research Problems: 1. What effect does leaf size and number have on plant transpiration rate? 2. What effect does air movement have on plant transpiration rate? Your hypothesis is: Materials: Four 50-milliliter graduated cylinders Modeling clay Cooking oil Cuttings from a large-leafed, herbaceous plant Water Electric fan Graph paper Procedures: 1. Take four stem cuttings (8 to 10 inches long) from stock plants. Choose stem cuttings with leaves of relatively equal size. Remove all but one leaf from two of the cuttings. Leave three or four leaves on each of the other two cuttings. 2. Add water to the four graduated cylinders. 3. Place the stem of the cuttings so they extend well below the water line in the graduated cylinders.

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165 4. Pour 2 milliliters of cooking oil on top of the water in the graduated cylinder to prevent evaporation losses. 5. Gently pack modeling clay around the stem at the cylinder opening to provide support for the plant. Be careful not to crush the stem. Try to establish initial water line near 40 milliliters. 6. Record the water level in each cylinder. 7. Place all four cylinders under the same environmental conditions (temperature, light, etc.) with one exception. Two of the cylinders (one with a single leaf and one with multiple leaves) should be placed in front of a low-speed fan. 8. Record the water level in each cylinder on a regular basis. 9. Summarize the data. Graph the results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Agriscience Applications: Transpiration is the loss of water through plant leaves. Over 90% of all water absorbed by the plant is lost through this process. This water loss occurs through the stomata, which are located on the underside of plant leaves. Some plants also have stomata on the upper side of the leaves. The stomata are pores that open and close under certain conditions. In addition to allowing water vapor to escape, the stomata also allow the inward movement of atmospheric carbon dioxide which is used in photosynthesis. Osmosis and diffusion are the primary means by which plants absorb water from the soil and release water through transpiration. Diffusion is the movement of molecules (water) from a region of higher concentration to a region of lower concentration. Transpiration water losses occur by diffusion. Osmosis is the diffusion of water through a differentially permeable membrane. Water enters the cell by osmosis then travels across several membranes until it moves into the xylem. It is then transported to the leaves where much of the water is diffused through the stomata. The upward movement of water from the roots to the leaves is known as the transpiration stream. As water is lost from the outer tissues of the leaf, water moves in from interior tissue. Differences in osmotic pressure between cell layers causes this suction of water from the roots to the leaves. This process is facilitated by the cohesion properties of water. Cohesion is the attraction between like molecules (water to water). Adhesion is the attraction between unlike molecules (water to plant tissue). Light, carbon dioxide concentrations, and water content in plant tissue affect the stomata. Air movement and humidity affect the opening and closing the stomata. Changes in turgor pressure of the guard cells cause the stomatal pores to open and close. When the stomata are closed, water loss is reduced. However, if the stomata are closed, carbon dioxide cannot enter the plant. Thus prohibiting photosynthesis from occurring. Maintaining adequate soil moisture is a critical management practice in plant growth for both indoor and outdoor growing conditions. For greenhouse crops, watering is probably the most time-consuming task required in growing a given crop. Fortunately, the high labor costs of maintaining proper moisture levels is somewhat offset by the relatively low cost of water as an input for greenhouse crops.

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166 In outdoor growing conditions, including vegetables, turf, and field crops, soil moisture fluctuates much more and reaches more extreme levels than in more controlled, indoor environments. Thus, maintaining adequate soil moisture levels in outdoor conditions is much more of a challenge, due to weather factors beyond the grower's control. Soil moisture levels are increased either by natural means (rainfall) or artificially via irrigation. Moisture losses occur primarily through the evaporation of water from the upper soil layers through the loss of water through leaf surfaces and other plant parts (transpiration). The rate of water loss as a result of transpiration is primarily dependent upon weather (i.e., temperature and humidity). Thus, growers must seasonally adjust their crop schedules according to the water intake and loss responses of the plants being grown. Data Summary End Day 1 Beginning Day 2 End of Day 2 Treatment Initial Reading Reading Net Change Reading Net Change Reading Net Change 1 leaf, no fan 3-4 leaves, no fan 1 leaf, fan 3-4 leaves, fan

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167 Course: Agriscience Foundations I Lesson: Propagating Plants Sexually (06.03.PL) Objectives: 1. Explain sexual reproduction of plants and its importance in plant survival. 2. Explain how pollination occurs and describe the different types of pollination. 3. Explain fertilization in flowering plants. 4. Explain the structures and formation of seeds. 5. Describe the conditions for seed germination. 6. Compare and contrast indoor and outdoor growing conditions. Student Performance Standards Addressed: 06.03: Propagate plants through sexual and asexual means. Equipment, Supplies, References, and Other Resources: References : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Interstate Publishers, Inc., 2003. Handouts : LS: 06.03.A.PL Environmental Factors Affecting Germination Student Handout LS: 06.03.B.PL Salinity and Seed Germination Student Handout Video : Teaching Demonstration Computer and video projection equipment : PowerPoint presentation or overhead projector o TM: 06.03a.A Pollination of a Flower o TM: 06.03a.B Fertilization of a Flower o TM: 06.03a.C Parts of a Bean Seed and a Corn Seed o TM: 06.03a.D Environmental Factors Necessary for Germination Equipment & Supplies : Examples of perfect flowers (Interest Approach) See materials list on lab sheet Audio recorder Audio tapes

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168 Teacher Directions Content Outline and/or Procedures REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.02.PL Determining the Importance of Photosynthesis and Respiration. INTEREST APPROACH Bring a couple of samples of perfect flowers, such as from a Hibiscus or a Lily plant, to class. Use them to show the students the various parts of a flower. Dissect the flower and demonstrate to students how the pollen gets from the anther to the stigma and then grows a pollen tube down through the style to fertilize the egg. Students should be able to see how the various parts of the flower interact for pollination to occur. OBJECTIVES 1. Explain sexual reproduction of plants and its importance in plant survival. I. Sexual reproduction involves flowers, fruits, and seeds. A. In sexual reproduction, sperm carried in the pollen from the male flower fuses with the egg in the female part of the flower. Both contribute to the genetic makeup of the new plant. B. Each time sexual reproduction occurs, there is a recombining of genetic material. As a result, some changes will occur. Some may be beneficial and some may not. As conditions of the environment change over time, the beneficial changes in plant genetics will allow the plant to survive. As plants continue to reproduce, they pass genes onto their offspring, which enables them to survive. 2. Explain how pollination occurs and describe the different types of pollination. TM: 06.03a.A Pollination of a Flower II. Pollination is the transfer of pollen from the male to the female part of a plant. A. Pollination occurs in many different ways: 1. Birds, insects, bats, and other animals are attracted to colorful, scented flowers. As they visit various flowers for food, they unintentionally pick up pollen and carry it from flower to flower. 2. Wind moves pollen from one flower to another. Plants that rely on wind generally do not produce colorful flowers with scents or nectar. B. Pollination of plants may occur in one of two ways:

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169 Teacher Directions Content Outline and/or Procedures 1. Self-pollination occurs when pollen from a plant pollinates a flower on the same plant. 2. Cross-pollination occurs when pollen from a plant pollinates a flower on a different plant. C. Once pollen lands on the stigma, it grows a pollen tube down the style to the ovary. The cell within the grain of pollen divides to form two sperm nuclei, which travel down the pollen tube to the embryo sac, fertilizing the egg. 3. Explain fertilization in flowering plants. TM: 06.03a.B Fertilization of a Flower III. Fertilization is necessary in flowering plants in order for the seed to develop. A. Fertilization in flowering plants is different from fertilization in any other living organism. In plants, both sperm nuclei in the pollen grain are involved in fertilization, resulting in a double fertilization. 1. The first fertilization occurs when one sperm fuses with the egg, resulting in a zygote. The resulting seed contains genetic information from both the male and female part of the flower. 2. The second fertilization occurs when the second sperm nucleus fuses with the two nuclei in the embryo sac. This will develop into the endosperm. The ovule of the flower will become the seed. B. When fertilization occurs and the parents are genetically different, the resulting offspring is said to be a hybrid. The advantage of hybrids is that the best traits of each parent, such as more vigorous growth, insect and disease resistance, or uniformity, may be expressed in the offspring. C. Genetic information is stored in every cell of a plant in long molecular chains made of Deoxyribonucleic acid (DNA). Segments of DNA, called genes, establish the code for life processes and the appearance of a plant. The genes are arranged in a set of chromosomes. Normal cells contain a double set of chromosomes and are said to be diploid. Reproductive cells, sperm and egg cells, have a single set of chromosomes and are said to be haploid. When fertilization occurs, the single sets of chromosomes are combined into the double set, one from each parent, resulting in traits from each parent being passed on to the offspring.

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170 Teacher Directions Content Outline and/or Procedures 4. Explain the structures and formation of seeds. TM: 06.03a.C Parts of a Bean Seed and a Corn Seed. IV. The function of the seed is to grow and develop into a mature plant that will produce more seeds. A. Seeds of flowering plants have several parts. 1. The seed coat is a protective shell surrounding the embryo and endosperm. It protects the seed from drying and from physical injury. The seed coat helps in determining when conditions for germination or the beginning of growth are right. 2. The embryo is a little plant that eventually grows and develops into the mature plant. It remains dormant within the seed. It has a stem, root, and one or two seed leaves called cotyledons. Monocot embryos have one seed leaf and dicot embryos have two seed leaves. 3. The endosperm is the food storage tissue in the seed, particularly in monocots. Dicots store their food in the two cotyledons. The food storage is necessary for the young seedling until it is able to manufacture its own food. B. After fertilization, the ovary wall enlarges and forms the fruit. The fruit may be fleshy or dry. 1. Fleshy fruit prevents the seeds from drying until they are mature. They also serve to help disperse the seeds. Animals are attracted to fruit, eat it with the seeds, and disperse or disseminate the seeds somewhere away from the parent plant. Examples of fleshy fruit include tomatoes, apples, pears, etc. 2. Dry fruit is found on plants such as the dandelion and maple trees. It does not depend on animals for dissemination, but may depend on wind or other methods of dissemination. 5. Describe the conditions for seed germination. TM: 06.03a.D Environmental Factors Necessary for Germination V. Seeds are designed to wait for favorable conditions to begin growth. They may lay dormant for many years before conditions allow them to begin to grow. A. Several environmental factors play key roles in seed germination. 1. Moisture or water is necessary for germination. 2. Air, particularly oxygen, is required for germination.

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171 Teacher Directions Content Outline and/or Procedures 3. Warm temperatures, between 40 and 104 degrees F, are necessary for germination. 4. Some plants require light or total darkness for germination. B. Stratification is when the seed must go through a period of cold temperatures before it will germinate. C. Scarification is the breaking down of the seed coat. Some seeds have such a hard, thick seed coat that they prevent the absorption of water to enable germination to occur. D. The germination process begins with the absorption of water. The seed swells and the embryo changes from a dormant state to an actively growing plant. The embryo draws energy from starches stored in the endosperm or cotyledons. The embryos root emerges from the seed and develops into the primary root. Then, the stem of the embryo sprouts upward. E. The quality of seed used is very important in production agriculture. Viable, or live, seed is important to ensure a high percentage of seed germination. Seed companies test seed to determine its germination percentage, which must be printed on the seed bag. Proper humidity and temperature during storage of the seeds help maintain seed viability. 5. High salt concentrations in the soil can have adverse effects on plant growth. A. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. B. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, and developing simple methods of measuring soil salinity concentrations in the soil.

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172 Teacher Directions Content Outline and/or Procedures C. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can lead to salt buildup in the growing medium and eventual death of the plant. 6. Compare and contrast indoor and outdoor growing conditions. VI. The grower has control over the quality and condition of seed, planting procedure, and weed competition, environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and/or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. B. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. REVIEW/SUMMARY Use the student learning objectives to summarize the lesson. Have students explain the content associated with each objective. Student responses can be used in determining which objectives need to be reviewed or taught from a different perspective. Questions at the end of chapters of textbooks covering this material may also be used in the review/summary. Complete Propagating Plants Sexually Worksheet. APPLICATION Complete LS: 06.03.A.PL Environmental Factors Affecting Germination and LS: 06.03.B.PL Salinity and Seed Germination.

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173 LS: 06.03.A.PL Teacher Instructions Environmental Factors Affecting Germination Interest Approach: (Present as follows.) Bring to class samples of a variety of seeds, including lettuce, marigold, grass, wheat and others. Ask students what conditions would be best for planting these seeds. Do all of these types of seed need the same conditions for optimal germination? If not, what are the unique requirements of each? Have one or more students plant some seeds in a flat or pot and then ask students to describe the ideal germination conditions for that seed type. Challenge their procedures (to maintain uncertainty in their minds about whether they have enough knowledge and skill to perform this task correctly). Agriscience Applications: (Discuss.) While the grower has control over the quality and condition of seed, planting procedure, and weed competition, environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and/or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. Research Problem: (Present and discuss.) How do light, oxygen, temperature and moisture affect seed germination? Purpose: (Present to class and discuss.) The purpose of this set of experiments is to examine the effects of the environmental conditions of light, oxygen, temperature, and moisture on seed germination. Optimal environmental conditions for selected plants will be generally determined. Through these experiments, students will be able to : 1. explain the effects of light, water, temperature, and oxygen on seed germination and why each of these elements is essential for germination; and

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174 2. explain and/or develop recommended practices for planting selected vegetable, agronomic, and horticultural crops in terms of the germination process. Materials: (Give to students.) lettuce or grass seeds bean seeds quart plastic bags (Ziplock) paper towels aluminum foil steel wool 2 jars with air-tight lids (pint or quart size) incubator or similar source for heat refrigerator eight 6 inch pots with potting soil or other soil mixture water gravel graph paper Procedures: (Give a copy to students and have them conduct the experiment.) (4 students per group) Effects of light on germination: 1. Divide 75 lettuce or grass seeds into three groups of 25. 2. Wet six paper towels and fold two at a time so that they will fit into the plastic bags. Place one set of folded towels in each of six plastic bags. 3. Place 25 lettuce/grass seeds on top of the paper towels in each of three plastic bags. 4. Wrap two of the lettuce/grass bags in aluminum foil to exclude light. 5. Place all bags in the same place under moderate conditions of light and room temperature. 6. After one day, unwrap the foil from one group of seeds and expose to light for one hour. Then re-cover with foil and label as to light exposure conditions. 7. Count the number of seeds that germinate after two and four days in each of the three bags. Record data and calculate the rate of germination. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of oxygen on germination: 1. Soak 20 bean seeds in water for 12 hours. 2. Obtain two jars with tight-fitting lids and line the sides with paper towels. 3. Loosely stuff paper towels into one jar to keep the lining pressed to the sides. 4. Loosely stuff paper towels and steel wool pads into the center of the other jar. 5. Evenly space ten bean seeds between the paper towels and wall of each jar. 6. Wet the contents of both jars leaving approximately two to three cm. of water in the bottom of each jar.

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175 7. Tightly seal each jar. 8. Observe the bean seeds daily for seven to ten days. 9. Observe the steel wool after seven to ten days and record your observations. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of temperature on germination: 1. Divide 75 bean seeds into three groups of 25. 2. Evenly space 25 seeds on top to two layers of moistened paper towels. Cover the seeds with two more layers of moistened paper towels. 3. Fold over the edges of the towels and roll up the towels and enclosed seeds into a tube (called a rag doll). Secure each end with a rubber band. Repeat this procedure until two more rag dolls are made. 4. Label each plastic bag with where the seed will be placed: cold, warm, control (room temperature). Put one rag doll in each bag and seal. 5. Place the bags in the assigned environment, positioning the rag dolls in an upright position: Warm environmentUse an incubator or heat source which will keep the seeds at approximately 85-90 F. ControlRoom temperature 68-76 F. Cold environmentPlace seeds in the refrigerator (35-40 F). 6. Record the number of seeds germinated at days 3, 5, and 7 for each treatment group and calculate the final germination percentage at day seven. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 7. Combine individual student data to obtain class average. Effects of moisture on germination: 1. Divide 80 bean seeds into equal groups of 10. Place a small amount of gravel in the bottom of eight 6-inch pots. Then fill with potting soil or another soil mixture to within one inch of the top of the pot. Slowly pour one liter of tap water into each pot and allow to drain well by tipping and shaking pot. 2. Plant ten seeds 1 cm deep in each of four pots and label. Plant ten seeds 4 cm deep in the other four pots and label accordingly. 3. Four different watering patterns will be tested for each of the two planting depths. Label one pot from each planting depth group as follows: no additional water; 80 ml on day 5; 40 ml on days 2, 4, 6, and 8; and 40 ml every day. Place pots in a sunny location, maintaining a temperature of at least 70 degrees F. 4. Add water as indicated by the treatment group for the next 9 days. 5. Record the number of seeds germinated in each pot on days 4, 7, and 10. Calculate the germination percentage. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.)

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176 Anticipated Findings: (Lead a discussion of these expected results before students conduct the experiments.) Actual numbers of seeds that germinate will vary, but greater exposure to light should be accompanied by greater germination of the lettuce/grass seeds and less germination by the onion sets. Seeds in oxygen-rich environments will germinate better. Seeds stored in the warmest temperatures should germinate the quickest and yield the highest percentage of germination. Moisture and seed depth will also have optimum levels. Data Summary: (Give sample data table to students and lead a discussion on how to summarize the data obtained from other parts of the experiment.) Observations should be taken in each of the four experiments as specified and the number of germinated seeds recorded. Have students complete simple data summary tables for each experiment. Students should graph the germination percentages in the moisture experiment by treatment group and number of days. In addition, students should observe and record the quality/healthiness of seedlings in the temperature, oxygen, and moisture experiments. Sample Data Summary Table Cold Room Temp. Warm Day # % # % # % 3 5 7 Conclusions: (Lead a discussion of these and other conclusions.) 1. Some seeds need light to germinate. 2. Seeds need oxygen to germinate. 3. Warmer temperatures increase germination for most seeds. 4. Seeds need moisture to germinate. 5. Optimum levels of moisture, temperature, and planting depth exist. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1. What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to answer your research question?) 3. What would you do differently in conducting this experiment a second time? 4. Why do some seeds need light to germinate? 5. Why is moisture needed for germination? 6. Why is good seed to soil contact needed for successful germination? 7. What happens if seeds are planted too deeply? Why?

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177 8. Why is oxygen needed for seed germination? 9. Are viable seeds alive? Explain. 10. Why dont most seeds need light to germinate, since light is necessary for photosynthesis? 11. What happens inside a seed to cause it to germinate? 12. Why did the seeds inside the jar with steel wool germinate poorly? 13. Why do cold temperatures slow or stall germination? Further Investigation: (Lead a discussion of these and other ideas.) 1. Compare the impact of these environmental factors for a variety of seed types. 2. Vary the amount of light in the first experiment to determine how much light per day is optimal for seeds that require light for germination.

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178 LS: 06.03.A.PL Student Handout ENVIRONMENTAL FACTORS AFFECTING GERMINATION Purpose and Objectives of Lab: The purpose of this set of experiments is to examine the effects of the environmental conditions of light, oxygen, temperature, and moisture on seed germination. Optimal environmental conditions for selected plants will be generally determined. Through these experiments, students will be able to : 1. explain the effects of light, water, temperature, and oxygen on seed germination and why each of these elements is essential for germination; and 2. explain and/or develop recommended practices for planting selected vegetable, agronomic, and horticultural crops in terms of the germination process. Research Problem: How do light, oxygen, temperature and moisture affect seed germination? Your hypothesis is: Materials: lettuce or grass seeds bean seeds quart plastic bags (Ziplock) paper towels aluminum foil steel wool 2 jars with air-tight lids (pint or quart size) incubator or similar source for heat refrigerator eight 6 inch pots with potting soil or other soil mixture water gravel graph paper Procedures: Effects of light on germination: 1. Divide 75 lettuce or grass seeds into three groups of 25. 2. Wet six paper towels and fold two at a time so that they will fit into the plastic bags. Place one set of folded towels in each of six plastic bags. 3. Place 25 lettuce/grass seeds on top of the paper towels in each of three plastic bags.

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179 4. Wrap two of the lettuce/grass bags in aluminum foil to exclude light. 5. Place all bags in the same place under moderate conditions of light and room temperature. 6. After one day, unwrap the foil from one group of seeds and expose to light for one hour. Then re-cover with foil and label as to light exposure conditions. 7. Count the number of seeds that germinate after two and four days in each of the three bags. Record data and calculate the rate of germination. Graph results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of oxygen on germination: 1. Soak 20 bean seeds in water for 12 hours. 2. Obtain two jars with tight-fitting lids and line the sides with paper towels. 3. Loosely stuff paper towels into one jar to keep the lining pressed to the sides. 4. Loosely stuff paper towels and steel wool pads into the center of the other jar. 5. Evenly space ten bean seeds between the paper towels and wall of each jar. 6. Wet the contents of both jars leaving approximately two to three cm. of water in the bottom of each jar. 7. Tightly seal each jar. 8. Observe the bean seeds daily for seven to ten days. 9. Observe the steel wool after seven to ten days and record your observations. Graph results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of temperature on germination: 1. Divide 75 bean seeds into three groups of 25. 2. Evenly space 25 seeds on top to two layers of moistened paper towels. Cover the seeds with two more layers of moistened paper towels. 3. Fold over the edges of the towels and roll up the towels and enclosed seeds into a tube (called a rag doll). Secure each end with a rubber band. Repeat this procedure until two more rag dolls are made. 4. Label each plastic bag with where the seed will be placed: cold, warm, control (room temperature). Put one rag doll in each bag and seal. 5. Place the bags in the assigned environment, positioning the rag dolls in an upright position: Warm environmentUse an incubator or heat source which will keep the seeds at approximately 85-90 F. ControlRoom temperature 68-76 F. Cold environmentPlace seeds in the refrigerator (35-40 F). 6. Record the number of seeds germinated at days 3, 5, and 7 for each treatment group and calculate the final germination percentage at day seven. Graph results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 7. Combine individual data to obtain class average.

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180 Effects of moisture on germination: 1. Divide 80 bean seeds into equal groups of 10. Place a small amount of gravel in the bottom of eight 6-inch pots. Then fill with potting soil or another soil mixture to within one inch of the top of the pot. Slowly pour one liter of tap water into each pot and allow to drain well by tipping and shaking pot. 2. Plant ten seeds 1 cm deep in each of four pots and label. Plant ten seeds 4 cm deep in the other four pots and label accordingly. 3. Four different watering patterns will be tested for each of the two planting depths. Label one pot from each planting depth group as follows: no additional water; 80 ml on day 5; 40 ml on days 2, 4, 6, and 8; and 40 ml every day. Place pots in a sunny location, maintaining a temperature of at least 70 degrees F. 4. Add water as indicated by the treatment group for the next 9 days. 5. Record the number of seeds germinated in each pot on days 4, 7, and 10. Calculate the germination percentage. Graph results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Agriscience Applications: While the grower has control over the quality and condition of seed, planting procedure, and weed competition; environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and /or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment.

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181 Data Summary Effect of Light on Germination Germination Treatment 2 Days 4 Days # % # % No Light Limited Light (1 hour) Constant Light Effects of Oxygen on Germination Day Bean Seed Observation 1 2 3 4 5 6 7 8 9 10 Steel Wool Observation after 7 10 days

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182 Effects of Temperature on Germination Cold Room Temp. Warm # % # % # % 3 5 7 Day Effects of Moisture on Germination Germination 1 cm Deep 4 cm Deep Day 4 Day 7 Day 10 Day 4 Day 7 Day 10 Treatment # % # % # % # % # % # % No additional water 80 ml on day 5 40 ml on days 2, 4, 6, and 8 40 ml every day

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183 LS: 06.03.B.PL Teacher Instructions Salinity and Seed Germination Interest Approach: (Present as follows.) Ask students to identify areas in Florida, the United States and around the world where field crops are irrigated. In what geographical areas does irrigated water provide essentially the only water received by the crop during a growing season? How do irrigated water and rain water differ? Which is better for plants? Why? Steer students in the direction of salt buildup in irrigated soils. Why does this occur? What effects does it have on crops? Why? Is this also a problem with container plants? Why or why not? As an alternative, bring a potted plant to class. Tell students you accidentally spilled some table salt onto the soil of a potted plant. Will this harm the plant? Why? Can the salt be washed out of the soil? Tie this into salt buildup in irrigated soils as described above. Continue to care for the plant in the usual way and let students observe the effects of the salt on the plant. Agriscience Applications: (Discuss.) High salt concentrations in the soil can have adverse effects on plant growth. Although plants require certain salt constituents for growth, some soils contain such large quantities of soluble salts that crop yields are decreased. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. A wide variety of major agronomic and horticultural crops are grown in this region of the United States. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Current standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, and developing simple methods of measuring soil salinity concentrations in the soil. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can lead to salt buildup in the growing medium and eventual death of the plant. Research Problem: (Present and discuss.) What are the effects of salt buildup in soils on seed germination and plant growth? Purpose of Lab: (Present to class and discuss.) The purpose of this experiment is to determine the effects of salt accumulation in soils on seed germination and plant growth. By participating in this lab, students will be able to: 1. explain the causes of soil salinity; 2. describe the general effects of salt accumulation in soils on plant growth and development; and

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184 3. explain why/how excessive salt concentrations in soil water have harmful effects on plants. Materials: (Give to students.) twelve 6" pots with drainage holes 20 lb. bag of potting soil 30 seeds each of peas, green beans, and sweet corn four 2-liter containers with lids or caps table salt gravel 50 ml beaker balance graph paper Procedures: (Give a copy to students and have them conduct the experiment.) (4 students per group) 1. Place about 2 cm of gravel in the bottom of each of 12 pots. Then add about 9 cm of potting soil to each pot so the soil line is about 3 cm from the top of the pot. 2. Add one liter of tap water to each pot and allow to drain well by tipping and shaking. 3. Make 4 irrigation solutions by adding 36g of NaCl (table salt) to container #4, 24g to container #3, 12g to container #2, and no salt to container #1. Fill each container with 2 liters of tap water. 4. Plant 10 green bean seeds 2 cm deep in each of 4 pots. Plant 4 pots of sweet corn and 4 pots of peas in the same manner. 5. Label all pots with seed type and 1 through 4 for irrigation solution. 6. Place the pots in a sunny location and keep moist (but not wet) by adding about 40 ml of the proper irrigation solution to each pot, preferably once a day in late morning. Seedlings should appear in 5 to 7 days. 7. Record the number of seeds germinated at days 3, 5, 7, 9, 11, 13, and 15 for each treatment group and calculate the final germination percentage at day fifteen. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 8. Combine individual student data to obtain class average. Anticipated Findings: (Lead a discussion of these expected results before students conduct the experiment.) The extent of the salinity effect depends upon plant species and even variety. Sensitivity to salinity also varies with stage of growth, with younger plants being more sensitive. Pots receiving the highest concentrations of salt in the irrigation water will have reduced germination rates and slower seedling growth rates. Results will vary, so multiple tests should be done simultaneously. Several days after germination, seedlings will begin to show signs of salt damage, which include curling up and dampening off of leaves. Some seeds will be unable to complete the germination process. In general, peas will be more resistant to salt concentrations, while progressive effects will be seen with green beans as the salt concentrations become higher.

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185 Data Summary: (Present a sample data summary table to students and lead a discussion on how to summarize all data from this experiment.) Record the number of seeds germinated on days 5, 7, 9, 11, 13, and 15. Keep watering and record data until one plant reaches the height of about 15 cm. Record all plant heights at that time. Have students use tables to summarize the data (see example that follows). At day 15 calculate average plant height for germinated seeds in each pot. Divide average plant height in pots 2, 3, and 4 by plant height in pot 1 to determine a ratio, based on the control. Plot for each seed type the number of seeds germinated as a function of time for each salinity level. Also plot percentage germination after 15 days by salinity level for each type of seed. Sample Data Summary Table Number of Seeds Germinated by Seed Type and Salt Concentration Irrig. Solu. #1 Irrig. Solu. #2 Irrig. Solu. #3 Irrig. Solu. #4 Day 3 peas corn beans Day 5 peas corn beans Day 7 peas corn beans Day 9 peas corn beans Day 11 peas corn beans Day 13 peas corn beans Day 15 peas corn beans

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186 Conclusions: (Lead a discussion of these and other conclusions.) 1. Salt accumulation in the soil decreases seed germination. Higher salt concentrations are associated with increased seed and plant injury. 2. Salt buildup negatively affects plant growth and causes plants to weaken and sometimes die. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to determine the effects of salt concentrations in the soil on seed germination and plant growth?) 3. What would you do differently in conducting this experiment a second time? 4. What causes salt accumulation in soils and growing media? 5. What practices do growers use to reduce salt buildup in soils? How do these practices work to lower salt accumulations? 6. What factors affect soil salinity? 7. What are the sources of salts that can accumulate in soils? 8. Why/how does salt in the soil solution affect seed viability and germination? 9. How is salt buildup in soils related to plant transpiration? Further Investigations: (Lead a discussion of these and other ideas.) 1. Use a variety of seed types, both agronomic and vegetable, to determine the differential effects of soil salinity on germination and seedling growth. 2. Use a combination of salt concentrations in the irrigation solution. Higher concentration will yield more dramatic results. 3. Use different soil types to examine the buffering effects of soil type on soil salinity and corresponding plant growth. 4. Test the degree of tolerance of various plants species to salts. Field crops, vegetable and house plants can be examined.

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187 LS: 06.03.B.PL Student Handout Salinity and Seed Germination Purpose of Lab: The purpose of this experiment is to determine the effects of soil accumulation in soils on seed germination and plant growth. By participating in this lab, students will be able to: 1. explain the cause of soil salinity; 2. describe the general effects of salt accumulation in soils on plant growth and development; and 3. explain why/how excessive salt concentrations in soil water have harmful effects on plants. Research Problem: What are the effects of salt buildup in soils on seed germination and plant growth? Your hypothesis is: Materials: twelve 6" pots with drainage holes 20 lb. bag of potting soil 30 seeds each of peas, green beans, and sweet corn four 2-liter containers with lids or caps table salt gravel 50 ml beaker balance graph paper Procedures: 1. Place about 2 cm of gravel in the bottom of each of 12 pots. Then add about 9 cm of potting soil to each pot so the soil line is about 3 cm from the top of the pot. 2. Add one liter of tap water to each pot and allow to drain well by tipping and shaking. 3. Make 4 irrigation solutions by adding 36g of NaCl (table salt) to container #4, 24g to container #3, 12g to container #2, and no salt to container #1. Fill each container with 2 liters of tap water. 4. Plant 10 green bean seeds 2 cm deep in each of 4 pots. Plant 4 pots of sweet corn and 4 pots of peas in the same manner. 5. Label all pots with seed type and 1 through 4 for irrigation solution.

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188 6. Place the pots in a sunny location and keep moist (but not wet) by adding about 40 ml of the proper irrigation solution to each pot, preferably once a day in late morning. Seedlings should appear in 5 to 7 days. 7. Record the number of seeds germinated at days 3, 5, 7, 9, 11, 13, and 15 for each treatment group and calculate the final germination percentage at day fifteen. Graph results (Be sure you have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 8. Combine individual data to obtain class average. Agriscience Applications: High soil water concentrations can have adverse effects on plant growth. Although plants require certain salt constituents for growth, some soils contain such large quantities of soluble salts that crop yields are decreased. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. A wide variety of major agronomic and horticultural crops are grown in this region of the United States. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Current standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, developing simple methods of measuring soil salinity concentrations in the soil. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can also lead to salt buildup in the growing medium and eventual death of the plant.

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189 Data Summary Number of Seeds Germinated by Seed Type and Salt Concentration Irrig. Solu. #1 Irrig. Solu. #2 Irrig. Solu. #3 Irrig. Solu. #4 Day 3 peas corn beans Day 5 peas corn beans Day 7 peas corn beans Day 9 peas corn beans Day 11 peas beans Day 13 peas corn beans Day 15 peas corn beans corn

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190 Investigative laboratory Approach Course: Agriscience Foundations I Lesson: Scientific Method (06.00.IL) Objectives: Student Performance Standards Addressed: 04.01 04.05 04.06 Equipment, Supplies, References, and Other Resources: References : Cooper, E. L. & Burton, L. D. (2004) Agriscience: Fundamentals and applications (3 rd Edition). Albany, NY: Delmar. (Unit 1). Handouts : Video : Computer and video projection equipment : Equipment & Supplies : 1. Identify the steps involved in the scientific method of investigation. 2. Define common terms used in agriscience research. 3. Properly report scientific findings. Osborne, E. W. (1994). Biological science applications in agriculture. Danville, IL: Interstate Publishers, Inc. (Chapter 1). The Experimentation Process handout LS: 06.00.IL Determining Mass Student Handout Teaching Demonstration PowerPoint presentation or Overhead projector o TM: 06.00.A The Scientific Method o TM: 06.00.B Agriscience Terms o TM: 06.00.C Guidelines for Constructing Charts and Graphs See materials list on lab sheet Audio recorder Audio tapes Teacher Directions Content Outline and/or Procedures REVIEW None new unit Push record on audio recorder Ask the students to explain the process by which scientists conduct investigations. Ask them to create a step by step procedure. Then ask for volunteers to share their procedure with the rest of the class. Compare student examples with the procedure suggested in the lesson. INTEREST APPROACH

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191 Teacher Directions Content Outline and/or Procedures OBJECTIVES 1. Identify the steps involved in the scientific method of investigation. TM: 06.00.A The Scientific Method A. The scientific method has five steps. 1. Define the problemusually stated as a question. a. What do you want to know? 2. Gather data (facts and information) about the problem. a. Summarize past experiences. b. Review other research results. 3. Suggest possible answers or solutions. a. A hypothesis is a prediction of the results of an experiment. b. Write the hypothesis before beginning the experiment. 4. Test the hypothesis. a. Conduct an experiment to test the hypothesis. b. Summarize the data collected in organized charts or tables. 5. Evaluate the results. a. Examine the findings of the experiment. b. Draw conclusions or judgments made on the basis of the findings. 2. Define common terms used in agriscience research. TM: 06.00.B Agriscience Terms B. Key terms used in agriscience experiments 1. Independent variable : Will affect another variable a. Known as treatment 2. Dependent variable : Observed variable; expected to change due to independent variable 3. Replication exact duplication a. Allows for validation 3. Properly report scientific findings TM: 06.00.C Guidelines for C. Data may be summarized and reported in many different ways. 1. Descriptive statistics are one common method. Common descriptive statistics are: a. Means which are averages b. Frequency distributions which are simply counts of how many times something occurred. c. Percentages

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192 Teacher Directions Content Outline and/or Procedures Constructing Charts and Graphs 2. Data can be visually summarized using charts and graphs. When constructing a graph, there are certain guidelines to follow: a. The independent variable (X) is reported on the horizontal axis (x-axis). b. The dependent variable (Y) is reported on the vertical axis (y-axis). c. Be sure to label the axis and title the graph. REVIEW/SUMMARY Use questioning to determine if students understand the content material of this lesson APPLICATION Complete LS 06.00.IL Determining Mass

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193 LS: 06.00.IL Teacher Instructions Determining Mass Interest Approach: (Present as follows.) Ask students, What is mass? Select a few students to offer their definition. Then hold up a piece of bubble gum and ask the students, What will happen to the mass (weight) of this piece of bubble gum when I chew it? !!Teacher note: Do NOT present the research problem to the students. Instead, challenge them to phrase the research question themselves. Research Problem: What effect does chewing have on the mass of bubble gum? Purpose: (Present to class and discuss.) The purpose of this experiment is to observe the effect chewing has on the mass of bubble gum. Also, this experiment will familiarize students with the scientific method. !!Teacher note: Pass out a copy of The Experimentation Process handout to each student. Have students work in lab groups to plan the design of their experiment by following the steps in this handout. Their written responses to each step in the experimentation process will constitute their design for this experiment. Allow groups to use different designs for their experiments as materials, time, and other resources allow. Require each group to develop a written design for their experiment BEFORE they proceed with conducting the experiment. !!Teacher note: Do NOT give the materials list and procedures to students. Instead, use them as a guide as you help students plan the design of their experiments. Materials: Balances or scales Bubble gum Graph paper Procedures: (2-4 students per group) 7. Weigh one piece of bubble gum. Record the mass. 8. Develop a hypothesis on the effect chewing will have on the mass of the bubble gum. Record your hypothesis.

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194 9. Chew the bubble gum for 30 seconds. Using the wrapper as a weigh paper, determine the mass of the bubble gum. 10. Repeat step #3 until bubble gum has been chewed for 5 minutes. 11. Graph the results of your findings. (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 12. Evaluate hypothesis !!Teacher note: Do NOT give the students sample formats for data summary tables. Instead challenge them to develop formats themselves and use the sample provided to guide your supervision of their work. Data Summary: 1:00 2:30 3:00 3:30 4:00 4:30 5:00 Observations should be taken of the experiment at regular intervals. Have students complete a simple data summary table stating their observations. Sample Data Summary Table Time 0:00 0:30 1:30 2:00 Mass !!Teacher note: Challenge your students to first identify in writing their conclusions, then use the following list to verify and modify their ideas. Conclusions: (Lead a discussion of these and other conclusions.) 1. Mass of the bubble gum decreased as it was chewed. 2. The decline in mass was greatest in the beginning. As time passed, the rate of decline slowed. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to answer the research question?) 3. What would you do differently in conducting this experiment a second time? 4. Why did the rate at which the mass changed slow down? !!Teacher note: Do NOT give the following ideas to your students. Instead, challenge them to identify their own ideas for further experimentation. Then lead a class discussion on how such experiments could be designed to answer their research objectives.

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195 Further Investigation: (Lead a discussion of these and other ideas.) 1 Compare different types of gum. 2. Instead of using time as the dependent variable, count the number of chews. !!Teacher note: Have each student or lab group select one of the ideas for further investigation and describe in writing the design for that experiment. (Address each step of the experimentation process see handout.) Questions: (Lead a discussion of these and other questions.) What was your hypothesis? Was it correct? What is the independent variable in this experiment? Answer: Mass What is the dependent variable in this experiment? Answer: Time

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196 LS: 06.00.IL Student Handout Determining Mass Purpose: The purpose of this experiment is to observe the effect chewing has on the mass of bubble gum. Also, this experiment will familiarize students with the scientific method. Research Problem: Your hypothesis is: Materials: (Use additional pages if needed.) Procedures: (Use additional pages if needed.) Data Summary: (Use additional pages if needed.) Questions: What was your hypothesis? Was it correct? What is the dependent variable in this experiment? What is the independent variable in this experiment?

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197 Course: Agriscience Foundations I Lesson: Examining Plant Structures and Functions (06.01.IL) Objectives: Student Performance Standards Addressed: 06.01: Describe the structure functions of plant parts including roots, stems, leaves, and flowers. Equipment, Supplies, References, and Other Resources: References : Interstate Publishers, Inc., 2003. Handouts : Video : Computer and video projection equipment : Equipment & Supplies : 1. Describe the cellular structure of plants. 2. Identify the major parts of plants and explain their functions. 3. Distinguish between plants based on seed cotyledons. 4. Explain the absorption and transport systems of plants. Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: Lab Sheet 06.01.IL Osmotic Turgescence (Pressure) Student Handout The Experimentation Process handout Teaching Demonstration PowerPoint presentation or Overhead projector o TM: 06.01.A Major Parts of a Plant Cell o TM: 06.01.H Comparison of Monocot and Dicot Seed o TM: 06.01.N Stomata o TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers o TM: 06.01.C Parts of a Typical Stem o TM: 06.01.E Specialized Stems o TM: 06.01.F Kinds of Roots o TM: 06.01.G Leaf types o TM: 06.01.K Arrangement of Tissues in Stems o TM: 06.01.L Roots o TM: 06.01.M Absorption Plant specimen (Interest Approach) See materials list on lab sheet Audio recorder Audio tapes

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198 Teacher Directions Content Outline and/or Procedures None new unit INTEREST APPROACH Push record on audio recorder Bring a small plant specimen (about 18 inches long) that has been pulled up so that leaves, stems, and roots are obvious. A specimen with flowers and/or fruit is preferred. Ask students to name the different parts of the specimen. As they do, have them describe the function of the part and how it is useful to humans. Move from the interest approach into the objectives and anticipated problems for the lesson. OBJECTIVES 1. Describe the cellular structure of plants. TM: 06.01. A Major Parts of a Plant Cell I. Cells are the structural basis of all living organisms. 1. All organisms are made of one or more cells. 2. Protoplasm in cells carries out life processes. 2. Cell specialization is the presence of cells that perform unique activities for a plant. (Flowers, leaves, roots, and stems are made of specialized cells.) C. Cells are formed into groups that work together. 1. Tissue is formed by groups of cells that are alike in activity and structure. 2. An organ is formed by tissues that work together to perform specific functions. 3. An organ system is a group of organs that works together to perform a function. D. Cell structure is the organization of the material that forms a cell. A. A cell is a tiny structure that forms the basic building blocks of plants. B. Plants are multi-cellular organisms, meaning that they have many cells. 1. Some cells have specific functions. 1. Plant cells have three major parts: wall, nucleus, and REVIEW

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199 Teacher Directions Content Outline and/or Procedures cytoplasm. 2. The cell wall surrounds the cell and controls the movement of materials into and out of the cell. 3. The nucleus is near the center of a cell and contains protoplasm, chromosomes, and other structures that control cell activity. 4. The cytoplasm is a thick solution inside the cell wall surrounding the nucleus. 5. Plant cells have many additional parts, including: chloroplasts, nucleolus, vacuole, mitochondria, and golgi body. TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers II. Plants are comprised of vegetative and reproductive parts. A. The major vegetative parts of plants are stems, leaves, and roots. 1. A stem is the central axis that supports the leaves, connects them with the roots, and transports water and other materials between the leaves and roots. Stems vary widely in appearance based on the species of plant. Stems may be vertical or horizontal and modified for climbing and to store water and food. Several specialized kinds of stems are important: 2. Identify the major parts of plants and explain their functions. TM: 06.01.C Parts of a Typical Stem TM: 06.01.E Specialized Stems a. RhizomeA rhizome is an underground stem that grows horizontally. It may grow adventitious roots and stems to develop as a separate plant. Examples include iris and wild ginger. b. TuberA tuber is an enlarged part of a stem that grows underground. A tuber can develop into a separate plant. Examples include potatoes and yams. c. TendrilA tendril is a threadlike leafless growth on a stem that attaches itself around other stems and objects. Tendrils typically grow in a spiral shape. After attaching itself, it holds the stem in position. Vines and climbing plants often have tendrils. Examples include sweet peas and cucumbers.

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200 Teacher Directions Content Outline and/or Procedures d. StolonA stolon is an above ground stem that grows horizontally and propagates new plants. Strawberries are well known as examples of plants that multiply using stolons. widely depending on the species of plant. Overall, roots can be classified as two major types: 3. A leaf is typically a large, flat, green organ attached to the stem. Leaves carry out photosynthesis, transpiration, and may store food. Shape, arrangement, and other features vary widely with the species of plant. There are two major kinds of leaves and three major types of arrangements: b. CompoundA compound leaf is divided into two or more leaflets TM: 06.01.F Kinds of Roots TM: 06.01.G Leaf types TM: 06.01.B Functions of Leaves, Stems, Roots, and Flowers e. BulbA bulb is an underground food-storage organ consisting of flattened, fleshy stem-like leaves with roots on the lower side. Examples of bulbs are onions and daffodils. f. CormA corm is a food storage structure at the end of a stem that grows underground. It is an enlarged or swollen stem base. Examples include gladiolus and crocus. g. CladophyllA cladophyll is a leaflike branch that resembles a leaf. It is also called a cladode. A cladophyll functions much like a leaf. 2. A root is the part of a plant that grows in the soil or other media. Roots anchor plants, absorb water and minerals, and store food. The root system structure varies a. FibrousA fibrous root system is made of many small roots and spread throughout the soil. b. TaprootA taproot system is made of one primary root with a number of small secondary roots. a. SimpleA simple leaf has only one blade. c. Leaf attachment also varies. This refers to the spacing and arrangement of leaves on the stem of a plant. The major kinds of attachment

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201 Teacher Directions Content Outline and/or Procedures are: In general, flowers produce pollen and ovules. Fertilization occurs when a pollen cell unites with an ovule. (1) AlternateAlternate leaf arrangement is one leaf at each node on a stem. (2) OppositeOpposite leaf arrangement is two leaves are attached at nodes opposite each other. (3) WhorledWhorled leaf arrangement is three or more leaves are at each node. B. The major reproductive parts of plants are flowers, seed, and fruit. 1. A flower is a part containing the reproductive organs. The types of flowers vary considerably. 2. Seed are formed by fertilized ovules and contain new plant life. 3. Fruit are the ovaries which develop to protect and nourish the developing seed. The kinds and nature of fruit vary widely. 3. Distinguish between plants based on seed cotyledons. TM: 06.01.H Comparison of Monocot and Dicot Seed III. A cotyledon is the fleshy structure within a seed that contains food for a developing embryo. A. Depending on the plant species, a seed may have one or two cotyledons. B. A plant species producing seed with one cotyledon is a monocotyledon, or monocot. 1. All grasses are monocots. Corn, wheat, oats, Bermuda grass, and sugarcane are examples of monocots. 2. Monocot plants have long, narrow leaves with parallel veins. All leaves branch from the main stem. 3. Stems are non-woody and tend to have a large area of pith in the center. C. A plant species producing seed with two cotyledons is a

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202 Teacher Directions Content Outline and/or Procedures dicotyledon, or dicot. 1. All plants other than grasses are dicots. Soybeans, trees, lettuce, sunflowers, and petunias are examples of dicots. 2. Dicot plants have broad leaves with a net-type of veins. 3. Stems are often long and branching. They may be woody or non-woody, depending on the plant species. 4. Explain the absorption and transport systems of plants. TM: 06.01.K Arrangement of Tissues in Stems TM: 06.01.L Roots TM: 06.01.M Absorption A. Roots have tiny root hairs covered with thin membranes that allow water and nutrients to enter. 1. Transpiration occurs through tiny stomata on leaves. TM: 06.01.N Stomata IV. Water and nutrients are primarily absorbed by the roots and transported throughout the plant by various tissues in the roots, stems, and leaves. 1. Osmosis is the movement of water from greater concentration in the soil or media to lower concentration in the root. 2. Water enters until the concentration in the root is equal to the concentration outside the root. 3. The water entering roots also carries inorganic substances known as nutrients. B. After absorption by roots, water is passed from cell to cell until it reaches the xylem. 1. Xylem is tissue, formed as tubes, that conducts water up the stem and to the leaves. 2. The petiole of the leaf takes the water from the xylem in the stem to the leaf veins, which distribute it throughout the leaf. C. Leaves lose water by transpiration. 2. Transpiration creates somewhat of an upward pull that assists the xylem in moving water and nutrients. D. Manufactured food is conducted from the leaves through the stems to the roots in phloem tissue.

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203 Teacher Directions Content Outline and/or Procedures 1. Phloem is the tissue that conducts sugars, proteins, hormones, dissolved materials, and salts from leaves to other parts of a plant. 2. The structure is observed as elongated sieve-type cells that form tube structures in stems. REVIEW/SUMMARY Focus the review and summary of the lesson on the student learning objectives. Have students explain the content associated with each objective. Use specimens of plant materials for students to use in demonstrating their knowledge of the objectives. Use student responses as the basis for reteaching. Complete Examining Plant Structures and Functions worksheet and/or have students complete questions at the end of the chapters in the text. APPLICATION Complete LS: 06.01.IL Osmotic Turgescence (Pressure)

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204 LS: 06.01.IL Teacher Instructions Osmotic Turgescence (Pressure) Interest Approach: (Present as follows.) Bring to class two sets of bean seeds. One of the sets should be soaked in water for approximately four hours prior to class. As the students to compare the two sets of seeds. Ask them why the seeds that had been soaked are larger. Agriscience Applications: (Discuss.) When cells in growing tissues split and enlarge as water and nutrients are absorbed and used to make new cellular materials, a tremendous force is produced. This force is called osmotic turgescence. The strength of the force depends upon characteristics of the seed. Hydraulic pressure causes a stretching effect on the cell walls, making cell enlargement (growth) possible. Plant cells are osmotic systems. The concentration of water is less inside the cell than outside. This osmotic process generates the cells internal hydraulic pressure. As water enters the cell, its volume and hydraulic pressure increase. !!Teacher note: Do NOT present the research problem to the students. Instead, challenge them to phrase the research question themselves. Research Problem: How much pressure is exerted by a seed as it takes up water for germination? Purpose: (Present to class and discuss.) The purpose of this experiment is to observe the pressure exerted by germinating seeds. !!Teacher note: Pass out a copy of The Experimentation Process handout to each student. Have students work in lab groups to plan the design of their experiment by following the steps in this handout. Their written responses to each step in the experimentation process will constitute their design for this experiment. Allow groups to use different designs for their experiments as materials, time, and other resources allow. Require each group to develop a written design for their experiment BEFORE they proceed with conducting the experiment. !!Teacher note: Do NOT give the materials list and procedures to students. Instead, use them as a guide as you help students plan the design of their experiments.

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205 Materials: lima bean seeds (or other large beans) dry, clean sand pen or pencil pint jar with lid masking tape box or pan Procedures: (4 students per group) Place an equal amount of beans and sand in a jar. Shake the jar to mix the beans and sand completely. Push the sand in tightly. Fill the jar to the top with sand. Wet the sand, but do not put enough water into the jar to flood it. Screw the lid on tightly Label each jar by putting your name on a piece of masking tape on the lid of the jar. Place the jar on a large pan or box in an area away from students. (This contains the mess of broken jars and aids in clean up afterwards.) !!Teacher note: Do NOT give the students sample formats for data summary tables. Instead challenge them to develop formats themselves and use the sample provided to guide your supervision of their work. Observe what happens to the jar after a few hours. Record observations. Data Summary: Observations should be taken of the experiment at regular intervals. Have students complete a simple data summary table stating their observations. Be sure student observations are written in complete sentences and with good sentence structure. Sample Data Summary Table Time Observation !!Teacher note: Challenge your students to first identify in writing their conclusions, then use the following list to verify and modify their ideas.

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206 Conclusions: (Lead a discussion of these and other conclusions.) 1. Expanding seeds create enough pressure to break glass jars. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to observe the pressure exerted by germinating seeds?) 5. Why did some jars not break at all? !!Teacher note: Do NOT give the following ideas to your students. Instead, challenge them to identify their own ideas for further experimentation. Then lead a class discussion on how such experiments could be designed to answer their research objectives. 3. What would you do differently in conducting this experiment a second time? 4. Why did some jars break more quickly than others? 6. What was the purpose of the sand in the experiment? Further Investigation: 3 Vary the temperature or light received by the jar to see if they have an effect on water uptake by the seed. 1 Compare different types of seeds. 2 Vary the amount of sand and seed placed in each jar. !!Teacher note: Have each student or lab group select one of the ideas for further investigation and describe in writing the design for that experiment. (Address each step of the experimentation process see handout.)

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207 LS: 06.01.IL Student Handout Osmotic Turgescence (Pressure) Purpose: The purpose of this experiment is to observe the pressure exerted by germinating seeds. Research Problem: Your hypothesis is: Materials: (Use additional pages if needed.) Procedures: (Use additional pages if needed.) Agriscience Applications: When cells in growing tissues split and enlarge as water and nutrients are absorbed and used to make new cellular materials, a tremendous force is produced. This force is called osmotic turgescence. The strength of the force depends upon characteristics of the seed. Hydraulic pressure causes a stretching effect on the cell walls, making cell enlargement (growth) possible. Plant cells are osmotic systems. The concentration of water is less inside the cell than outside. This osmotic process generates the cells internal hydraulic pressure. As water enters the cell, its volume and hydraulic pressure increase. Data Summary: (Use additional pages if needed.)

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208 Course: Agriscience Foundations I Lesson: Determining the Importance of Photosynthesis and Respiration (06.02.IL) Objectives: 1. Explain photosynthesis and its importance. 2. Write the chemical equation for photosynthesis and explain it. 3. Explain how light and dark reactions differ. 4. Define respiration and explain why it is important. 5. List four factors that affect the rate of respiration. 6. Explain the importance of transpiration to plants. Student Performance Standards Addressed: 06.02: Describe the processes of plant growth including photosynthesis, respiration, and nutrient uptake. Equipment, Supplies, References, and Other Resources: References : Interstate Publishers, Inc., 2003. Handouts : Video : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: LS: 06.02.IL Transpiration in Plants Student Handout The Experimentation Process handout Computer and video projection equipment Teaching Demonstration : PowerPoint presentation or Overhead projector o TM: 06.02.D Comparison of Photosynthesis and Respiration o TM: 06.02.F Transpiration and Gas Exchange in Leaves o TM: 06.02.G Factors Affecting the Rate of Transpiration Equipment & Supplies o TM: 06.02.A Energy Flow o TM: 06.02.B Photosynthesis Equation o TM: 06.02.C Two Major Phases of Photosynthesis o TM: 06.02.E Factors Affecting the Rate of Respiration : See materials list on lab sheet Audio recorder Audio tapes

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209 Teacher Directions REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.01.IL Examining Plant Structures and Functions. INTEREST APPROACH Start the lesson by shutting off the lights in the classroom. Ask the students if they could survive and continue to make energy if they were kept in the dark. Ask students what effect complete darkness would have on other mammals. Now ask the students what effect complete darkness would have on plants. OBJECTIVES 1. Explain photosynthesis and its importance. TM: 06.02.A Energy Flow TM: 06.02.C Two Major Phases of Photosynthesis TM: 06.02.B Photosynthesis Equation I. Photosynthesis is the manufacture of food by plant cells. A. Sugar is the major product of photosynthesis and provides energy for the plant. B. There are two phases to the photosynthesis process. 1. Energy gatheringPlant leaves soak up sunlight. 2. Sugar makingPlants convert energy from sunlight into stored chemical energy. a. Chemical energy rearranges carbon dioxide in the plant in the presence of chlorophyll to form sugar. b. Glucose, a simple sugar, is formed. C. Photosynthesis is the most important reaction on earth. All life forms are dependent on the reaction. 1. Occurs in the chloroplasts 2. CO2 + light + chlorophyll + H2O C6H12O6 (glucose) + H2O + O2 D. In order for photosynthesis to occur, several things must be present. 1. Chlorophyllgreen colored substance in plants. 2. LightLeaves absorb necessary energy from the suns rays or artificial light. 3. Carbon DioxideEnters the plant through structure called Content Outline and/or Procedures

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210 Teacher Directions Content Outline and/or Procedures stomata in the leaves. Carbon dioxide is split during photosynthesis. 4. WaterWater is also split during photosynthesis. 2. Write the chemical equation for photosynthesis and explain it. TM: 06.02.B Photosynthesis Equation II. Photosynthesis is a series of chemical reactions that yields sugars, water, and oxygen. A. The chemical equation of photosynthesis can be written in words: Six molecules of carbon dioxide plus twelve molecules of water in combination with a healthy plant and some form of light energy, to make one molecule of sugar plus six molecules of water and six molecules of oxygen. B. The products of photosynthesis include carbohydrates in the form of sugars and starches as well as water and oxygen. 3. Explain how light and dark reactions differ. III. Photosynthesis is a series of complex reactions that have been divided into two major phases. These two major phases have been named the light and dark reactions. A. Light Reactions 1. The light reactions are also known as light dependent reactions. Light allows energy to be released in the form of ATP which can be used by the plant in the splitting of water and the release of oxygen. 2. The pigments in chloroplasts absorb light energy to form NADPH and ATP to be used in the breakdown of CO2 in the dark reactions. B. Dark Reaction 1. Also known as light independent reactions. 2. A chemical known as RuBP (rubilose biphosphate) absorbs carbon. Carbon dioxide and RuBP join together and go through a process called the Calvin cycle. The Calvin cycle reduces carbon dioxide to manufacture carbohydrates. The NADPH and ATP synthesis from the light reactions provide the energy needed to power the Calvin cycle. 3. As a result of the Calvin cycle, one molecule of glucose is formed. 4. Define respiration and explain why it is important. IV. Respiration is the process by which an organism provides its cells with oxygen so energy can be released from digested food. Respiration takes place in all living cells at all

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211 Teacher Directions Content Outline and/or Procedures TM: 06.02.D Comparison of Photosynthesis and Respiration times. A. Mitochondria are energy processing factories for plants. Respiration takes place in the mitochondria of all cells. B. Respiration yields the opposite results as photosynthesis. The process of photosynthesis absorbs energy, consumes carbon dioxide and releases oxygen. Respiration uses energy, consumes oxygen and releases carbon dioxide. 5. List four factors that affect the rate of respiration. TM: 06.02.E Factors Affecting the Rate of Respiration V. Temperature, oxygen, soil conditions, and light can affect the rate of respiration. A. TemperatureThere is a direct relationship between respiration and temperature, as the temperature increases so does the rate of respiration. B. OxygenOxygen is required for respiration to take place. As oxygen levels decrease so does the rate of respiration. C. Soil conditionsSoil containing large quantities of water cause the rate of respiration to decrease because of the lack of oxygen. D. LightThe amount of energy produced by photosynthesis in low light conditions is reduced. Therefore the amount of energy available to conduct respiration is lower. 6. Explain the importance of transpiration in plants. TM: 06.02.F Transpiration and Gas Exchange in Leaves TM: 06.02.G Factors Affecting the Rate of Transpiration VI. Transpiration in plants is the loss of water by evaporation through structures called stomata. Stomata are pores or openings in the plant that allow for the exchange of water and other substances. Transpiration in plants is similar to perspiration in humans. A. Water molecules and transpiration together form a force that is essential for water movement through plants. 1. As water evaporates through the stomata of plant, it creates a pull that aids in the absorption of water by the roots. (An analogy of using a straw to drink will help students to visualize this process.) 2. Transpiration is a vital link in the hydrologic cycle. Ninety-nine percent of all water taken in by the plant is lost to transpiration. Therefore, transpiration contributes significantly to the generation of rainfall.

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212 Teacher Directions Content Outline and/or Procedures B. Factors affecting the rate of transpiration include: 1. Wind speedthe relationship between wind speed and transpiration is a direct relationship. 2. Temperatureas temperature increases so does the rate of transpiration because the plant uses transpiration as a mechanism to cool itself. Once again there is a direct relationship between temperature and transpiration. 3. HumidityHumidity influences the rate of transpiration because if the air is already saturated with water vapor, there will be a decrease in the rate of evaporation. 4. DroughtIf the plant is experiencing drought conditions it will close the stomata to prevent needed water from escaping. When the plants stomata are closed transpiration does not take place. REVIEW/SUMMARY Focus the review and summary of the lesson around the student learning objectives. Call on students to explain the content associated with each objective. Questions at the end of each chapter in the recommended textbooks may also be used in the review/summary. Complete the Determining the Importance of Photosynthesis and Respiration worksheet. APPLICATION Complete LS: 06.02.IL Transpiration in Plants

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213 LS: 06.02.IL Teacher Instructions Transpiration in Plants Interest Approach: (Present as follows) Ask three to five students to volunteer participate in a race. Give each volunteer a penny, a pipette, and cup of water. The rules of the competition are simple, the person who can put the largest numbers of water drops on the top of the penny without getting the table wet wins. You may also ask for another set of students to volunteer to help count the number of drops on each students penny. After the race is over, ask the competitors to describe to the rest of the class what happened. Why were you able to get so many drops on the penny? Describe the properties of adhesion and cohesion. Relate to transpiration in plants. Agriscience Applications: (Discuss) Transpiration is the loss of water through plant leaves. Over 90% of all water absorbed by the plant is lost through this process. This water loss occurs through the stomata, which are located on the underside of plant leaves. Some plants also have stomata on the upper side of the leaves. The stomata are pores that open and close under certain conditions. In addition to allowing water vapor to escape, the stomata also allow the inward movement of atmospheric carbon dioxide which is used in photosynthesis. Osmosis and diffusion are the primary means by which plants absorb water from the soil and release water through transpiration. Diffusion is the movement of molecules (water) from a region of higher concentration to a region of lower concentration. Transpiration water losses occur by diffusion. Osmosis is the diffusion of water through a differentially permeable membrane. Water enters the cell by osmosis then travels across several membranes until it moves into the xylem. It is then transported to the leaves where much of the water is diffused through the stomata. The upward movement of water from the roots to the leaves is known as the transpiration stream. As water is lost from the outer tissues of the leaf, water moves in from interior tissue. Differences in osmotic pressure between cell layers causes this suction of water from the roots to the leaves. This process is facilitated by the cohesion properties of water. Cohesion is the attraction between like molecules (water to water). Adhesion is the attraction between unlike molecules (water to plant tissue). Light, carbon dioxide concentrations, and water content in plant tissue affect the stomata. Air movement and humidity affect the opening and closing the stomata. Changes in turgor pressure of the guard cells cause the stomatal pores to open and close. When the stomata are closed, water loss is reduced. However, if the stomata are closed, carbon dioxide cannot enter the plant. Thus prohibiting photosynthesis from occurring. Maintaining adequate soil moisture is a critical management practice in plant growth for both indoor and outdoor growing conditions. For greenhouse crops, watering is probably the most time-consuming task required in growing a given crop. Fortunately, the high labor costs of maintaining proper moisture levels is somewhat offset by the relatively low cost of water as an input for greenhouse crops.

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214 In outdoor growing conditions, including vegetables, turf, and field crops, soil moisture fluctuates much more and reaches more extreme levels than in more controlled, indoor environments. Thus, maintaining adequate soil moisture levels in outdoor conditions is much more of a challenge, due to weather factors beyond the grower's control. Soil moisture levels are increased either by natural means (rainfall) or artificially via irrigation. Moisture losses occur primarily through the evaporation of water from the upper soil layers through the loss of water through leaf surfaces and other plant parts (transpiration). The rate of water loss as a result of transpiration is primarily dependent upon weather (i.e., temperature and humidity). Thus, growers must seasonally adjust their crop schedules according to the water intake and loss responses of the plants being grown. !!Teacher note: Do NOT present the research problem to the students. Instead, challenge them to phrase the research question themselves. Research Problems: 1. What effect does leaf size and number have on plant transpiration rate? 2. What effect does air movement have on plant transpiration rate? Purpose: (Present to class and discuss) The purpose of this experiment is to observe the general rate of transpiration in plants and to examine the effects of wind on transpiration rate. Through this lab, students will be able to: 1. describe the biological process of transpiration in plants; 2. identify the factors that affect transpiration and explain why and how these effects are realized; 3. measure transpiration rates in given test plants; and 4. explain the relationship between transpiration and soil moisture management practices on plant growth. !!Teacher note: Pass out a copy of The Experimentation Process handout to each student. Have students work in lab groups to plan the design of their experiment by following the steps in this handout. Their written responses to each step in the experimentation process will constitute their design for this experiment. Allow groups to use different designs for their experiments as materials, time, and other resources allow. Require each group to develop a written design for their experiment BEFORE they proceed with conducting the experiment. !!Teacher note: Do NOT give the materials list and procedures to students. Instead, use them as a guide as you help students plan the design of their experiments.

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215 Materials: Four 50-milliliter graduated cylinders Modeling clay Cooking oil Cuttings from a large-leafed, herbaceous plant Water Electric fan Graph paper Procedures: (4 students per group) 10. Take four stem cuttings (8 to 10 inches long) from stock plants. Choose stem cuttings with leaves of relatively equal size. Remove all but one leaf from two of the cuttings. Leave three or four leaves on each of the other two cuttings. !!Teacher note: Do NOT give the students sample formats for data summary tables. Instead challenge them to develop formats themselves and use the sample provided to guide your supervision of their work. 11. Add water to the four graduated cylinders. 12. Place the stem of the cuttings so they extend well below the water line in the graduated cylinders. 13. Pour 2 milliliters of cooking oil on top of the water in the graduated cylinder to prevent evaporation losses. 14. Gently pack modeling clay around the stem at the cylinder opening to provide support for the plant. Be careful not to crush the stem. Try to establish initial water line near 40 milliliters. 15. Record the water level in each cylinder. 16. Place all four cylinders under the same environmental conditions (temperature, light, etc.) with one exception. Two of the cylinders (one with a single leaf and one with multiple leaves) should be placed in front of a low-speed fan. 17. Record the water level in each cylinder on a regular basis. 18. Summarize the data. Graph the results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Data Summary: Observations should be taken of the experiment at regular intervals. Have students complete the simple data summary table. Students should graph the water loss the occurred during the time of the experiment.

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216 End Day 1 Beginning Day 2 End of Day 2 Treatment Initial Reading Reading Net Change Reading Net Change Reading Net Change 1 leaf, no fan 3-4 leaves, no fan 1 leaf, fan 3-4 leaves, fan !!Teacher note: Challenge your students to first identify in writing their conclusions, then use the following list to verify and modify their ideas. Conclusions: (Lead a discussion of these and other conclusions.) 1. Moisture is lost through the leaves. 2. The greater the number of leaves (leaf surface area), the greater the loss from transpiration. 3. Increased airflow (up to a certain speed) will increase the rate of transpiration. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1. What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures allow you to answer the research question? 3. What would you do differently in conducting this experiment a second time? 4. What effect would transpiration have on the way you would manage a greenhouse? 5. What plants would be more susceptible to greater losses of moisture due to transpiration? 6. Why were herbaceous plants selected for this experiment? 7. Why does air movement tend to increase the rate of transpiration? 8. What would happen if transpiration rate exceeded the rate at which the plant could replenish the water in its tissues? 9. At what point does an increase in air speed decrease transpiration? Why? 10. What is the relationship between rate of transpiration and leaf surface area? 11. What causes water to be pulled upward into the leaf stems? !!Teacher note: Do NOT give the following ideas to your students. Instead, challenge them to identify their own ideas for further experimentation. Then lead a class discussion on how such experiments could be designed to answer their research objectives.

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217 Further Investigation: (Lead a discussion of these and other ideas.) 1. Examine the effects of additional environmental factors such as light intensity, temperature, and humidity on the rate of transpiration in plants. 2. Examine the rate of transpiration in plants that are growing under various degrees of soil moisture. !!Teacher note: Have each student or lab group select one of the ideas for further investigation and describe in writing the design for that experiment. (Address each step of the experimentation process see handout.)

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218 LS: 06.02.IL Student Handout Transpiration in Plants Purpose of this Lab: The purpose of this experiment is to observe the general rate of transpiration in plants and to examine the effects of wind on transpiration rate. Through this lab, students will be able to: 1. describe the biological process of transpiration in plants; 2. identify the factors that affect transpiration and explain why and how these effects are realized; 3. measure transpiration rates in given test plants; and 4. explain the relationship between transpiration and soil moisture management practices on plant growth. Research Problems: Your hypothesis is: Materials: (Use additional pages if needed.) Procedures: (Use additional pages if needed.)

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219 Agriscience Applications: Transpiration is the loss of water through plant leaves. Over 90% of all water absorbed by the plant is lost through this process. This water loss occurs through the stomata, which are located on the underside of plant leaves. Some plants also have stomata on the upper side of the leaves. The stomata are pores that open and close under certain conditions. In addition to allowing water vapor to escape, the stomata also allow the inward movement of atmospheric carbon dioxide which is used in photosynthesis. Osmosis and diffusion are the primary means by which plants absorb water from the soil and release water through transpiration. Diffusion is the movement of molecules (water) from a region of higher concentration to a region of lower concentration. Transpiration water losses occur by diffusion. Osmosis is the diffusion of water through a differentially permeable membrane. Water enters the cell by osmosis then travels across several membranes until it moves into the xylem. It is then transported to the leaves where much of the water is diffused through the stomata. The upward movement of water from the roots to the leaves is known as the transpiration stream. As water is lost from the outer tissues of the leaf, water moves in from interior tissue. Differences in osmotic pressure between cell layers causes this suction of water from the roots to the leaves. This process is facilitated by the cohesion properties of water. Cohesion is the attraction between like molecules (water to water). Adhesion is the attraction between unlike molecules (water to plant tissue). Light, carbon dioxide concentrations, and water content in plant tissue affect the stomata. Air movement and humidity affect the opening and closing the stomata. Changes in turgor pressure of the guard cells cause the stomatal pores to open and close. When the stomata are closed, water loss is reduced. However, if the stomata are closed, carbon dioxide cannot enter the plant. Thus prohibiting photosynthesis from occurring. Maintaining adequate soil moisture is a critical management practice in plant growth for both indoor and outdoor growing conditions. For greenhouse crops, watering is probably the most time-consuming task required in growing a given crop. Fortunately, the high labor costs of maintaining proper moisture levels is somewhat offset by the relatively low cost of water as an input for greenhouse crops. In outdoor growing conditions, including vegetables, turf, and field crops, soil moisture fluctuates much more and reaches more extreme levels than in more controlled, indoor environments. Thus, maintaining adequate soil moisture levels in outdoor conditions is much more of a challenge, due to weather factors beyond the grower's control. Soil moisture levels are increased either by natural means (rainfall) or artificially via irrigation. Moisture losses occur primarily through the evaporation of water from the upper soil layers through the loss of water through leaf surfaces and other plant parts (transpiration). The rate of water loss as a result of transpiration is primarily dependent upon weather (i.e., temperature and humidity). Thus, growers must seasonally adjust their crop schedules according to the water intake and loss responses of the plants being grown. Data Summary (Use additional pages)

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220 Course: Agriscience Foundations I Lesson: Propagating Plants Sexually (06.03.IL) Objectives: 1. Explain sexual reproduction of plants and its importance in plant survival. 2. Explain how pollination occurs and describe the different types of pollination. 3. Explain fertilization in flowering plants. 4. Explain the structures and formation of seeds. 5. Describe the conditions for seed germination. 6. Compare and contrast indoor and outdoor growing conditions. Student Performance Standards Addressed: 06.03: Propagate plants through sexual and asexual means. Equipment, Supplies, References, and Other Resources: References : Interstate Publishers, Inc., 2003. Handouts : Video : Computer and video projection equipment : Equipment & Supplies : Cooper, Elmer L. Agriscience Fundamentals and Applications, Third Edition. Albany, New York: Delmar Publishers, Inc., 2004. Lee, Jasper S. and Diana L. Turner. AgriScience, Third Edition. Danville, Illinois: LS: 06.03.A.IL Environmental Factors Affecting Germination Student Handout LS: 06.03.B.IL Salinity and Seed Germination Student Handout The Experimentation Process handout Teaching Demonstration PowerPoint presentation or overhead projector o TM: 06.03a.A Pollination of a Flower o TM: 06.03a.B Fertilization of a Flower o TM: 06.03a.C Parts of a Bean Seed and a Corn Seed o TM: 06.03a.D Environmental Factors Necessary for Germination Examples of perfect flowers (Interest Approach) See materials list on lab sheets Audio recorder Audio tapes

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221 Teacher Directions Content Outline and/or Procedures REVIEW Push record on audio recorder Quickly review the objectives of Lesson 06.02.IL Determining the Importance of Photosynthesis and Respiration. INTEREST APPROACH Bring a couple of samples of perfect flowers, such as from a Hibiscus or a Lily plant, to class. Use them to show the students the various parts of a flower. Dissect the flower and demonstrate to students how the pollen gets from the anther to the stigma and then grows a pollen tube down through the style to fertilize the egg. Students should be able to see how the various parts of the flower interact for pollination to occur. OBJECTIVES 1. Explain sexual reproduction of plants and its importance in plant survival. I. Sexual reproduction involves flowers, fruits, and seeds. A. In sexual reproduction, sperm carried in the pollen from the male flower fuses with the egg in the female part of the flower. Both contribute to the genetic makeup of the new plant. B. Each time sexual reproduction occurs, there is a recombining of genetic material. As a result, some changes will occur. Some may be beneficial and some may not. As conditions of the environment change over time, the beneficial changes in plant genetics will allow the plant to survive. As plants continue to reproduce, they pass genes onto their offspring, which enables them to survive. 2. Explain how pollination occurs and describe the different types of pollination. TM: 06.03a.A Pollination of a Flower II. Pollination is the transfer of pollen from the male to the female part of a plant. A. Pollination occurs in many different ways: 1. Birds, insects, bats, and other animals are attracted to colorful, scented flowers. As they visit various flowers for food, they unintentionally pick up pollen and carry it from flower to flower. 2. Wind moves pollen from one flower to another. Plants that rely on wind generally do not produce colorful flowers with scents or nectar. B. Pollination of plants may occur in one of two ways:

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222 Teacher Directions Content Outline and/or Procedures 1. Self-pollination occurs when pollen from a plant pollinates a flower on the same plant. 2. Cross-pollination occurs when pollen from a plant pollinates a flower on a different plant. C. Once pollen lands on the stigma, it grows a pollen tube down the style to the ovary. The cell within the grain of pollen divides to form two sperm nuclei, which travel down the pollen tube to the embryo sac, fertilizing the egg. 3. Explain fertilization in flowering plants. TM: 06.03a.B Fertilization of a Flower III. Fertilization is necessary in flowering plants in order for the seed to develop. A. Fertilization in flowering plants is different from fertilization in any other living organism. In plants, both sperm nuclei in the pollen grain are involved in fertilization, resulting in a double fertilization. 1. The first fertilization occurs when one sperm fuses with the egg, resulting in a zygote. The resulting seed contains genetic information from both the male and female part of the flower. 2. The second fertilization occurs when the second sperm nucleus fuses with the two nuclei in the embryo sac. This will develop into the endosperm. The ovule of the flower will become the seed. B. When fertilization occurs and the parents are genetically different, the resulting offspring is said to be a hybrid. The advantage of hybrids is that the best traits of each parent, such as more vigorous growth, insect and disease resistance, or uniformity, may be expressed in the offspring. C. Genetic information is stored in every cell of a plant in long molecular chains made of Deoxyribonucleic acid (DNA). Segments of DNA, called genes, establish the code for life processes and the appearance of a plant. The genes are arranged in a set of chromosomes. Normal cells contain a double set of chromosomes and are said to be diploid. Reproductive cells, sperm and egg cells, have a single set of chromosomes and are said to be haploid. When fertilization occurs, the single sets of chromosomes are combined into the double set, one from each parent, resulting in traits from each parent being passed on to the offspring.

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223 Teacher Directions Content Outline and/or Procedures 4. Explain the structures and formation of seeds. TM: 06.03a.C Parts of a Bean Seed and a Corn Seed. IV. The function of the seed is to grow and develop into a mature plant that will produce more seeds. A. Seeds of flowering plants have several parts. 1. The seed coat is a protective shell surrounding the embryo and endosperm. It protects the seed from drying and from physical injury. The seed coat helps in determining when conditions for germination or the beginning of growth are right. 2. The embryo is a little plant that eventually grows and develops into the mature plant. It remains dormant within the seed. It has a stem, root, and one or two seed leaves called cotyledons. Monocot embryos have one seed leaf and dicot embryos have two seed leaves. 3. The endosperm is the food storage tissue in the seed, particularly in monocots. Dicots store their food in the two cotyledons. The food storage is necessary for the young seedling until it is able to manufacture its own food. B. After fertilization, the ovary wall enlarges and forms the fruit. The fruit may be fleshy or dry. 1. Fleshy fruit prevents the seeds from drying until they are mature. They also serve to help disperse the seeds. Animals are attracted to fruit, eat it with the seeds, and disperse or disseminate the seeds somewhere away from the parent plant. Examples of fleshy fruit include tomatoes, apples, pears, etc. 2. Dry fruit is found on plants such as the dandelion and maple trees. It does not depend on animals for dissemination, but may depend on wind or other methods of dissemination. 5. Describe the conditions for seed germination. TM: 06.03a.D Environmental Factors Necessary for Germination V. Seeds are designed to wait for favorable conditions to begin growth. They may lay dormant for many years before conditions allow them to begin to grow. A. Several environmental factors play key roles in seed germination. 1. Moisture or water is necessary for germination. 2. Air, particularly oxygen, is required for germination.

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224 Teacher Directions Content Outline and/or Procedures 3. Warm temperatures, between 40 and 104 degrees F, are necessary for germination. 4. Some plants require light or total darkness for germination. B. Stratification is when the seed must go through a period of cold temperatures before it will germinate. C. Scarification is the breaking down of the seed coat. Some seeds have such a hard, thick seed coat that they prevent the absorption of water to enable germination to occur. D. The germination process begins with the absorption of water. The seed swells and the embryo changes from a dormant state to an actively growing plant. The embryo draws energy from starches stored in the endosperm or cotyledons. The embryos root emerges from the seed and develops into the primary root. Then, the stem of the embryo sprouts upward. E. The quality of seed used is very important in production agriculture. Viable, or live, seed is important to ensure a high percentage of seed germination. Seed companies test seed to determine its germination percentage, which must be printed on the seed bag. Proper humidity and temperature during storage of the seeds help maintain seed viability. 5. High salt concentrations in the soil can have adverse effects on plant growth. A. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. B. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, and developing simple methods of measuring soil salinity concentrations in the soil.

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225 Teacher Directions Content Outline and/or Procedures C. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can lead to salt buildup in the growing medium and eventual death of the plant. 6. Compare and contrast indoor and outdoor growing conditions. VI. The grower has control over the quality and condition of seed, planting procedure, and weed competition, environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. B. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. A. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and/or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. REVIEW/SUMMARY Use the student learning objectives to summarize the lesson. Have students explain the content associated with each objective. Student responses can be used in determining which objectives need to be reviewed or taught from a different perspective. Questions at the end of chapters of textbooks covering this material may also be used in the review/summary. Complete Propagating Plants Sexually Worksheet. APPLICATION Complete LS: 06.03.A.IL Environmental Factors Affecting Germination and LS: 06.03.B.IL Salinity and Seed Germination

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226 LS: 06.03.A.IL Teacher Instructions Environmental Factors Affecting Germination Interest Approach: (Present as follows.) Bring to class samples of a variety of seeds, including lettuce, marigold, grass, wheat and others. Ask students what conditions would be best for planting these seeds. Do all of these types of seed need the same conditions for optimal germination? If not, what are the unique requirements of each? Have one or more students plant some seeds in a flat or pot and then ask students to describe the ideal germination conditions for that seed type. Challenge their procedures (to maintain uncertainty in their minds about whether they have enough knowledge and skill to perform this task correctly). Agriscience Applications: (Discuss.) While the grower has control over the quality and condition of seed, planting procedure, and weed competition, environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and/or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. !!Teacher note: Do NOT present the research problem to the students. Instead, challenge them to phrase the research question themselves. Research Problem: How do light, oxygen, temperature and moisture affect seed germination? Purpose: (Present to class and discuss.) The purpose of this set of experiments is to examine the effects of the environmental conditions of light, oxygen, temperature, and moisture on seed germination. Optimal environmental conditions for selected plants will be generally determined. Through these experiments, students will be able to :

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227 1. explain the effects of light, water, temperature, and oxygen on seed germination and why each of these elements is essential for germination; and 2. explain and/or develop recommended practices for planting selected vegetable, agronomic, and horticultural crops in terms of the germination process. !!Teacher note: Pass out a copy of The Experimentation Process handout to each student. Have students work in lab groups to plan the design of their experiment by following the steps in this handout. Their written responses to each step in the experimentation process will constitute their design for this experiment. Allow groups to use different designs for their experiments as materials, time, and other resources allow. Require each group to develop a written design for their experiment BEFORE they proceed with conducting the experiment. !!Teacher note: Do NOT give the materials list and procedures to students. Instead, use them as a guide as you help students plan the design of their experiments. Materials: lettuce or grass seeds bean seeds quart plastic bags (Ziplock) paper towels aluminum foil steel wool 2 jars with air-tight lids (pint or quart size) incubator or similar source for heat refrigerator eight 6 inch pots with potting soil or other soil mixture water gravel graph paper Procedures: (4 students per group) Effects of light on germination: 1. Divide 75 lettuce or grass seeds into three groups of 25. 2. Wet six paper towels and fold two at a time so that they will fit into the plastic bags. Place one set of folded towels in each of six plastic bags. 3. Place 25 lettuce/grass seeds on top of the paper towels in each of three plastic bags. 4. Wrap two of the lettuce/grass bags in aluminum foil to exclude light. 5. Place all bags in the same place under moderate conditions of light and room temperature. 6. After one day, unwrap the foil from one group of seeds and expose to light for one hour. Then re-cover with foil and label as to light exposure conditions.

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228 7. Count the number of seeds that germinate after two and four days in each of the three bags. Record data and calculate the rate of germination. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of oxygen on germination: 1. Soak 20 bean seeds in water for 12 hours. 2. Obtain two jars with tight-fitting lids and line the sides with paper towels. 3. Loosely stuff paper towels into one jar to keep the lining pressed to the sides. 4. Loosely stuff paper towels and steel wool pads into the center of the other jar. 5. Evenly space ten bean seeds between the paper towels and wall of each jar. 6. Wet the contents of both jars leaving approximately two to three cm. of water in the bottom of each jar. 7. Tightly seal each jar. 8. Observe the bean seeds daily for seven to ten days. 9. Observe the steel wool after seven to ten days and record your observations. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Effects of temperature on germination: 1. Divide 75 bean seeds into three groups of 25. 2. Evenly space 25 seeds on top to two layers of moistened paper towels. Cover the seeds with two more layers of moistened paper towels. 3. Fold over the edges of the towels and roll up the towels and enclosed seeds into a tube (called a rag doll). Secure each end with a rubber band. Repeat this procedure until two more rag dolls are made. Cold environmentPlace seeds in the refrigerator (35-40 F). 4. Label each plastic bag with where the seed will be placed: cold, warm, control (room temperature). Put one rag doll in each bag and seal. 5. Place the bags in the assigned environment, positioning the rag dolls in an upright position: Warm environmentUse an incubator or heat source which will keep the seeds at approximately 85-90 F. ControlRoom temperature 68-76 F. 6. Record the number of seeds germinated at days 3, 5, and 7 for each treatment group and calculate the final germination percentage at day seven. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 7. Combine individual student data to obtain class average.

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229 Effects of moisture on germination: 1. Divide 80 bean seeds into equal groups of 10. Place a small amount of gravel in the bottom of eight 6-inch pots. Then fill with potting soil or another soil mixture to within one inch of the top of the pot. Slowly pour one liter of tap water into each pot and allow to drain well by tipping and shaking pot. 2. Plant ten seeds 1 cm deep in each of four pots and label. Plant ten seeds 4 cm deep in the other four pots and label accordingly. 3. Four different watering patterns will be tested for each of the two planting depths. Label one pot from each planting depth group as follows: no additional water; 80 ml on day 5; 40 ml on days 2, 4, 6, and 8; and 40 ml every day. Place pots in a sunny location, maintaining a temperature of at least 70 degrees F. 4. Add water as indicated by the treatment group for the next 9 days. 5. Record the number of seeds germinated in each pot on days 4, 7, and 10. Calculate the germination percentage. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) Anticipated Findings: Actual numbers of seeds that germinate will vary, but greater exposure to light should be accompanied by greater germination of the lettuce/grass seeds and less germination by the onion sets. Seeds in oxygen-rich environments will germinate better. Seeds stored in the warmest temperatures should germinate the quickest and yield the highest percentage of germination. Moisture and seed depth will also have optimum levels. !!Teacher note: Do NOT give the students sample formats for data summary tables. Instead challenge them to develop formats themselves and use the sample provided to guide your supervision of their work. Data Summary: Observations should be taken in each of the four experiments as specified and the number of germinated seeds recorded. Have students complete simple data summary tables for each experiment. Students should graph the germination percentages in the moisture experiment by treatment group and number of days. In addition, students should observe and record the quality/healthiness of seedlings in the temperature, oxygen, and moisture experiments.

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230 Sample Data Summary Tables Effect of Light on Germination Germination 4 Days # % # % Limited Light (1 hour) Constant Light Treatment 2 Days No Light Effects of Oxygen on Germination Day Bean Seed Observation 1 2 3 4 5 6 7 8 10 9 Steel Wool Observation after 7 10 days Effects of Temperature on Germination Cold Room Temp. Warm Day # % # % # % 3 5 7

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231 Effects of Moisture on Germination Germination 1 cm Deep 4 cm Deep Day 4 Day 7 Day 10 Day 4 Day 7 Day 10 Treatment # % # % # % # # % # % % No additional water 40 ml every day 80 ml on day 5 40 ml on days 2, 4, 6, and 8 !!Teacher note: Challenge your students to first identify in writing their conclusions, then use the following list to verify and modify their ideas. Conclusions: (Lead a discussion of these and other conclusions.) 3. Warmer temperatures increase germination for most seeds. 1. Some seeds need light to germinate. 2. Seeds need oxygen to germinate. 4. Seeds need moisture to germinate. 5. Optimum levels of moisture, temperature, and planting depth exist. Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1. What were the most difficult aspects of conducting this experiment? 3. What would you do differently in conducting this experiment a second time? 4. Why do some seeds need light to germinate? 6. Why is good seed to soil contact needed for successful germination? 7. What happens if seeds are planted too deeply? Why? 11. What happens inside a seed to cause it to germinate? 2. Did the experimental procedures produce the desired results? (Were you able to answer your research question?) 5. Why is moisture needed for germination? 8. Why is oxygen needed for seed germination? 9. Are viable seeds alive? Explain. 10. Why dont most seeds need light to germinate, since light is necessary for photosynthesis? 12. Why did the seeds inside the jar with steel wool germinate poorly?

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232 13. Why do cold temperatures slow or stall germination? !!Teacher note: Do NOT give the following ideas to your students. Instead, challenge them to identify their own ideas for further experimentation. Then lead a class discussion on how such experiments could be designed to answer their research objectives. Further Investigation: (Lead a discussion of these and other ideas.) 1. Compare the impact of these environmental factors for a variety of seed types. 2. Vary the amount of light in the first experiment to determine how much light per day is optimal for seeds that require light for germination. !!Teacher note: Have each student or lab group select one of the ideas for further investigation and describe in writing the design for that experiment. (Address each step of the experimentation process see handout.)

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233 LS: 06.03.A.IL Student Handout ENVIRONMENTAL FACTORS AFFECTING GERMINATION Purpose and Objectives of Lab: The purpose of this set of experiments is to examine the effects of the environmental conditions of light, oxygen, temperature, and moisture on seed germination. Optimal environmental conditions for selected plants will be generally determined. Through these experiments, students will be able to : 2. explain and/or develop recommended practices for planting selected vegetable, agronomic, and horticultural crops in terms of the germination process. 1. explain the effects of light, water, temperature, and oxygen on seed germination and why each of these elements is essential for germination; and Research Problem: Your hypothesis is: Materials: (Use additional pages if needed.) Procedures: (Use additional pages if needed.) Effects of light on germination: Effects of oxygen on germination:

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234 Effects of temperature on germination: Effects of moisture on germination: Agriscience Applications: While the grower has control over the quality and condition of seed, planting procedure, and weed competition; environmental conditions cannot be controlled in outdoor settings. The grower must be able to correctly interpret planting conditions and adjust timing and planting procedures accordingly. A major advantage of growing plants in greenhouses is that critical environmental conditions of moisture, temperature, oxygen and light can accurately be controlled. Control and /or correct adaptation to environmental conditions enhance overall seed germination and seedling establishment. Germination percentage affects plant population, which in turn affects profit potential of a given crop. In outdoor settings soil and seedbed conditions have a direct influence on moisture and oxygen availability for seed germination in vegetable, agronomic and horticulture crops. In addition, all plants have soil temperature ranges that will promote acceptable germination rates. Thus, growers must know the temperature ranges for their crops and time their plantings accordingly in order to ensure good germination and seedling establishment. Data Summary (Use additional pages if needed.)

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235 LS: 06.03.B.IL Teacher Instructions Salinity and Seed Germination Interest Approach: (Present as follows.) Ask students to identify areas in Florida, the United States and around the world where field crops are irrigated. In what geographical areas does irrigated water provide essentially the only water received by the crop during a growing season? How do irrigated water and rain water differ? Which is better for plants? Why? Steer students in the direction of salt buildup in irrigated soils. Why does this occur? What effects does it have on crops? Why? Is this also a problem with container plants? Why or why not? As an alternative, bring a potted plant to class. Tell students you accidentally spilled some table salt onto the soil of a potted plant. Will this harm the plant? Why? Can the salt be washed out of the soil? Tie this into salt buildup in irrigated soils as described above. Continue to care for the plant in the usual way and let students observe the effects of the salt on the plant. Agriscience Applications: (Discuss.) High salt concentrations in the soil can have adverse effects on plant growth. Although plants require certain salt constituents for growth, some soils contain such large quantities of soluble salts that crop yields are decreased. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. A wide variety of major agronomic and horticultural crops are grown in this region of the United States. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Current standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, and developing simple methods of measuring soil salinity concentrations in the soil. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can lead to salt buildup in the growing medium and eventual death of the plant. !!Teacher note: Do NOT present the research problem to the students. Instead, challenge them to phrase the research question themselves. Research Problem: What are the effects of salt buildup in soils on seed germination and plant growth?

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236 Purpose of Lab: (Present to class and discuss.) The purpose of this experiment is to determine the effects of salt accumulation in soils on seed germination and plant growth. By participating in this lab, students will be able to: 1. explain the causes of soil salinity; 2. describe the general effects of salt accumulation in soils on plant growth and development; and 3. explain why/how excessive salt concentrations in soil water have harmful effects on plants. !!Teacher note: Pass out a copy of The Experimentation Process handout to each student. Have students work in lab groups to plan the design of their experiment by following the steps in this handout. Their written responses to each step in the experimentation process will constitute their design for this experiment. Allow groups to use different designs for their experiments as materials, time, and other resources allow. Require each group to develop a written design for their experiment BEFORE they proceed with conducting the experiment. !!Teacher note: Do NOT give the materials list and procedures to students. Instead, use them as a guide as you help students plan the design of their experiments. Materials: twelve 6" pots with drainage holes 20 lb. bag of potting soil 30 seeds each of peas, green beans, and sweet corn four 2-liter containers with lids or caps table salt gravel 50 ml beaker balance graph paper Procedures: (4 students per group) 1. Place about 2 cm of gravel in the bottom of each of 12 pots. Then add about 9 cm of potting soil to each pot so the soil line is about 3 cm from the top of the pot. 2. Add one liter of tap water to each pot and allow to drain well by tipping and shaking. 3. Make 4 irrigation solutions by adding 36g of NaCl (table salt) to container #4, 24g to container #3, 12g to container #2, and no salt to container #1. Fill each container with 2 liters of tap water. 4. Plant 10 green bean seeds 2 cm deep in each of 4 pots. Plant 4 pots of sweet corn and 4 pots of peas in the same manner. 5. Label all pots with seed type and 1 through 4 for irrigation solution.

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237 6. Place the pots in a sunny location and keep moist (but not wet) by adding about 40 ml of the proper irrigation solution to each pot, preferably once a day in late morning. Seedlings should appear in 5 to 7 days. 7. Record the number of seeds germinated at days 3, 5, 7, 9, 11, 13, and 15 for each treatment group and calculate the final germination percentage at day fifteen. Graph results (Be sure students have properly identified the independent and dependent variables and that the graphs are labeled appropriately.) 8. Combine individual student data to obtain class average. Anticipated Findings: The extent of the salinity effect depends upon plant species and even variety. Sensitivity to salinity also varies with stage of growth, with younger plants being more sensitive. Pots receiving the highest concentrations of salt in the irrigation water will have reduced germination rates and slower seedling growth rates. Results will vary, so multiple tests should be done simultaneously. Several days after germination, seedlings will begin to show signs of salt damage, which include curling up and dampening off of leaves. Some seeds will be unable to complete the germination process. In general, peas will be more resistant to salt concentrations, while progressive effects will be seen with green beans as the salt concentrations become higher. !!Teacher note: Do NOT give the students sample formats for data summary tables. Instead challenge them to develop formats themselves and use the sample provided to guide your supervision of their work. Data Summary: Record the number of seeds germinated on days 5, 7, 9, 11, 13, and 15. Keep watering and record data until one plant reaches the height of about 15 cm. Record all plant heights at that time. Have students use tables to summarize the data (see example that follows). At day 15 calculate average plant height for germinated seeds in each pot. Divide average plant height in pots 2, 3, and 4 by plant height in pot 1 to determine a ratio, based on the control. Plot for each seed type the number of seeds germinated as a function of time for each salinity level. Also plot percentage germination after 15 days by salinity level for each type of seed.

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238 Sample Data Summary Table Number of Seeds Germinated by Seed Type and Salt Concentration Irrig. Solu. #1 Irrig. Solu. #2 Irrig. Solu. #3 Irrig. Solu. #4 Day 3 peas corn beans Day 5 peas corn beans Day 7 peas corn beans Day 9 peas corn beans Day 11 peas corn beans Day 13 peas corn beans Day 15 peas corn beans !!Teacher note: Challenge your students to first identify in writing their conclusions, then use the following list to verify and modify their ideas. Conclusions: (Lead a discussion of these and other conclusions.) 1. Salt accumulation in the soil decreases seed germination. Higher salt concentrations are associated with increased seed and plant injury. 2. Salt buildup negatively affects plant growth and causes plants to weaken and sometimes die.

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239 Discussion: (Use a supervised study session or whole class discussion to answer the following questions.) 1 What were the most difficult aspects of conducting this experiment? 2. Did the experimental procedures produce the desired results? (Were you able to determine the effects of salt concentrations in the soil on seed germination and plant growth?) 3. What would you do differently in conducting this experiment a second time? 4. What causes salt accumulation in soils and growing media? 5. What practices do growers use to reduce salt buildup in soils? How do these practices work to lower salt accumulations? 6. What factors affect soil salinity? 7. What are the sources of salts that can accumulate in soils? 8. Why/how does salt in the soil solution affect seed viability and germination? 9. How is salt buildup in soils related to plant transpiration? !!Teacher note: Do NOT give the following ideas to your students. Instead, challenge them to identify their own ideas for further experimentation. Then lead a class discussion on how such experiments could be designed to answer their research objectives. Further Investigations: (Lead a discussion of these and other ideas.) 1. Use a variety of seed types, both agronomic and vegetable, to determine the differential effects of soil salinity on germination and seedling growth. 2. Use a combination of salt concentrations in the irrigation solution. Higher concentration will yield more dramatic results. 3. Use different soil types to examine the buffering effects of soil type on soil salinity and corresponding plant growth. 4. Test the degree of tolerance of various plants species to salts. Field crops, vegetable and house plants can be examined. !!Teacher note: Have each student or lab group select one of the ideas for further investigation and describe in writing the design for that experiment. (Address each step of the experimentation process see handout.)

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240 LS: 06.03.B.IL Student Handout Salinity and Seed Germination Purpose of Lab: The purpose of this experiment is to determine the effects of soil accumulation in soils on seed germination and plant growth. By participating in this lab, students will be able to: 1. explain the cause of soil salinity; 2. describe the general effects of salt accumulation in soils on plant growth and development; and 3. explain why/how excessive salt concentrations in soil water have harmful effects on plants. Research Problem: Your hypothesis is: Materials: (Use additional pages if needed.) Procedures: (Use additional pages if needed.)

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241 Agriscience Applications: High soil water concentrations can have adverse effects on plant growth. Although plants require certain salt constituents for growth, some soils contain such large quantities of soluble salts that crop yields are decreased. Soil salinity is most severe in arid, irrigated areas around the world. Salinity may affect as much as 30% of all irrigated land in the U.S., primarily in the southwestern part of the country. A wide variety of major agronomic and horticultural crops are grown in this region of the United States. In field conditions dissolved salts are usually applied in the irrigation water. Enough salt may accumulate in a few years to reduce the productivity of the soil. Current standard practice in irrigation is to add enough water to permit some drainage to help remove salt buildup in the soil. Artificial drainage is a major investment. Research now underway is aimed at determining optimal amounts of irrigated water to apply, developing simple methods of measuring soil salinity concentrations in the soil. Salt buildup may also be a problem in greenhouse crops and indoor plants if drainage outlets are not provided in the growing container. Inadequate watering, even with well designed containers, can also lead to salt buildup in the growing medium and eventual death of the plant. Data Summary (Use additional pages if needed.)

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APPENDIX C c. labor 3. What is the standard industry test for determining seed viability? CONTENT KNOWLEDGE PRETEST Instructions on completing the answer sheet: 1. Enter your name in the spaces provided. (Last Name, First Initial, Middle Initial) 2. Darken the appropriate circle under each letter of your name. 3. In the section titled ID No. enter the individual code number given to you by your teacher in the first five spaces. (This will be a five digit number.) 4. Darken the appropriate circle under each number of the individual code. 5. Leave the sections titled Section and Special Codes blank. 6. In the Test Form Code section, darken the circle corresponding to the Test Form code found on the top of this exam. Directions: Read the questions completely and carefully, then darken the circle on the answer sheet that corresponds to the best answer for each of the following questions. 1. Greenhouses offer more control than crops grown in field conditions over which of the following variables? a. machinery costs b. environmental conditions d. all variables 2. You observe two plants of the same species. You are told that one plant is the daughter of the other. You observe that the daughter plant has a slightly different leaf structure. With this information you can hypothesize that the daughter plant was produced through which propagation method? a. sexual propagation b. asexual propagation a. TZ test b. warm germination test c. cold germination test d. excised embryo test 242

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243 4.For most grass seeds, how will additional light during germination affect germination rate? a. decrease b. increase c. not affect 5. Seeds that you planted several weeks ago still havent germinated. In reexamining your seeds you observe that pots containing your seeds were flooded with water. What factor is most likely the cause for the seeds not germinating? a. low temperature b. lack of fertility c. lack of moisture d. lack of oxygen 6. How does gibberellic acid affects seed germination rates? a. increasing the response to plant toxins b. increasing the concentration of soil moisture c. increasing cell division 7. When seeds are planted too deeply, why is germination rate reduced? a. a fungus often develops due to excessive moisture b. sunlight is not available c. seed rot occurs d. food reserves are used up before roots can begin nutrient uptake 9. Which part of a seed is actually a plant in an arrested state of development? 8. Seed germination involves the action of enzymes which: a. convert starch into sugar b. convert starch into amino acids c. convert starch to gibberellic acid a. endosperm b. plantlet c. embryo a. is unaffected a. embryonic growth 10. In general, as soil temperature decreases, what will happen to germination rate? b. decreases c. increases 11. What causes seed swelling at the beginning of germination? b. water intake c. cell division d. enzymatic activity

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244 12. Why are wet, compacted soils likely to result in lower germination rates? a. increased oxygen b. increased water c. decreased oxygen d. inadequate watering d. Ohio 13. What is commonly the cause of salt buildup in soils? a. under-fertilization b. overwatering c. use of pesticides 14. In which of the following states is soil salinity of most concern? a. Arizona b. Tennessee c. Kansas 15. Why are well drained soils less likely to suffer from salt buildup? a. water moves rapidly downward through the soil, leaving salts on the soil surface b. water runoff is greater c. water moving downward through the soil carries salts with it d. water evaporates from the soil surface more quickly 16. What would you expect for a plant that is grown in direct sun, given adequate amounts of fertilizer and water? a. evaporation to be low b. transpiration to be high c. photosynthesis to be low 17. Why shouldnt germinating seeds come in contact with fertilizers? a. salt has a negative effect on water intake b. seed rot is a greater concern c. excessive growth will occur d. the fertilizer will dissolve too quickly 18. A farmer lives in a salinity affected area. What would be the best strategy for him to get the most productive yields from his land? a. irrigate occasionally, especially when it is hot b. use a lot of chemicals on his fields to dissolve the soil c. use moldboard plowing d. plant salt-tolerant plant varieties 19. What is water loss through plant tissues called? a. dehydration b. evaporation c. transpiration

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245 c. flowers 20. Where does water loss in plant tissues primarily occur? a. leaves b. stems d. roots 21. When managing a greenhouse, how should you water? a. to incorporate nutrient solutions b. to keep soils wet c. to avoid extremes in water availability d. to replenish dry soils 22. Approximately what percentage of all water absorbed by a plants root system is given off through plant tissues? a. 49% b. 67% c. 90% d. 99% 23. What are the tiny pores through which water vapor escapes from the plant tissue called? a. micropores b. stomata c. macropores d. xylem 24. As water is lost from plant tissues, differences in which variable creates a suction effect that pulls more water into the plant through the root system? a. osmotic pressure b. tissue thickness c. humidity d. air pressure 25. Plants lose their ______ as water content decreases in plant cells a. leaves b. vigor c. turgidity d. phloem 26. Which plant has the highest rate of transpiration? a. a small plant in a bedroom b. a large plant in a garden c. a small plant in a garden d. a large plant on a porch

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246 27. In general, what happens to the amount of water loss through the plant tissue as the temperature drops on a cool, fall day? a. decreases b. cycles up and down c. remains constant d. increases 28. On a warm, sunny day with a slight breeze, the loss of water through the plant tissues will be: a. increased by the breeze due to lower humidity around the plant tissues b. unaffected by the breeze c. decreased by the breeze due to higher humidity around the plant tissues d. increased by the breeze due to movement of the plant tissues 29. The loss of water through the tissues of most plants: a. occurs during lighted, warmer times of the day b. is unrelated to processes in the plant c. occurs at the same rate throughout the day and night d. occurs during the dark, cooler hours only 30. What occurs when water is lost through plant tissues at a faster rate than water can be absorbed by the root system? a. wilting b. growth c. symbiosis d. photosynthesis 31. What is formed by groups of cells that are alike in activity and structure? a. Nucleus b. Organ c. Tissue 32. What is the movement of water from greater concentration in the soil to lower concentration in the root is called? a. absorption b. osmosis c. intake 33. Which of the following is NOT a component of the process of photosynthesis? a. nitrogen b. light c. carbon dioxide d. oxygen

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247 34. What is the process by which an organism provides its cells with oxygen is called? a. photosynthesis b. light reaction c. transpiration d. respiration 35. Some seeds must go through a period of cold temperatures before they will germinate. What is this process called? a. stratification b. cold fusion c. scarification d. dormination 36. Which of the following provide the energy needed to power the Calvin cycle? a. ATP, carbon dioxide, and oxygen b. NADPH and ATP c. photosynthesis and ATP d. respiration and RuBP 37. Where does a young seedling gains the food it needs until it is able to manufacturer its own? a. embryo b. endosperm c. soil 38. What happens to a plants transpiration rate as the amount of oxygen in the environment surrounding a plant decreases? a. decreases b. stays the same c. increases 39. Which of the following processes creates a pull that aids in the absorption of water by the roots? a. photosynthesis b. respiration c. transpiration d. cell division 40. Which of the following is NOT a function of plant roots? a. anchor plants b. produce food c. absorb water and minerals d. store food

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248 41. Which of the following best describes the characteristics of a dicot plant? a. narrow leaves with parallel veins b. many small roots c. two seed leaves d. three or more leaves at each node 42. Which of the following conducts water up the stem and to the leaves? a. xylem b. roots c. phloem 43. After fertilization, the ovary wall enlarges and forms which part of the plant? a. seed b. style c. fruit 44. Which of the following is NOT a cell organelle? a. vacuole b. stolon c. mitochondria d. nucleolus 45. Which of the following plant part lists are in the order in which water enters a plant? a. leaf, stem, root b. root, xylem, leaf c. root, phloem, leaf d. leaf, xylem, root 46. What would be the best way to determine the effect temperature has on transpiration? a. Place a plant in a heated room. Measure the time it takes the plant to become wilted. b. Place two plants inside a jar of water. Measure the temperature and the amount of water that is lost from the jar. c. Place two plants in two separate jars of water. Place them at two different temperatures and seal the top of the jars. Record the amount of water that is lost from the jar. 47. In an experiment in which petroleum jelly is placed on the underside of some of the leaves of a plant, what would be the expected outcome? a. transpiration would increase b. photosynthesis would increase c. there would be no effect on the plant d. transpiration would decrease

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249 48. Which of the following leaf arrangements has the highest transpiration rate? a. alternate b. opposite c. whorled d. leaf arrangement does not affect transpiration rate. 49. What is produced when water, carbon dioxide, and light energy are in the presence of a healthy green plant? a. complex sugar b. starch c. oxygen 50. How does the process of osmosis aid in plant nutrient uptake? a. water leaves the root until the pressure inside the root is less than the pressure outside the root b. water and nutrients are absorbed by the roots until the nutrient concentration is high. c. water moves from a greater concentration in the soil to a lower concentration in the root.

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APPENDIX D CONTENT KNOWLEDGE POSTTEST Instructions on completing the answer sheet: 1. Enter your name in the spaces provided. (Last Name, First Initial, Middle Initial) 2. Darken the appropriate circle under each letter of your name. 3. In the section titled ID No. enter the individual code number given to you by your teacher in the first five spaces. (This will be a five digit number.) 4. Darken the appropriate circle under each number of the individual code. 5. Leave the sections titled Section and Special Codes blank. 6. In the Test Form Code section, darken the circle corresponding to the Test Form code found on the top of this exam. Directions: Read the questions completely and carefully, then darken the circle on the answer sheet that corresponds to the best answer for each of the following questions. 1.You observe two plants of the same species. You are told that one plant is the daughter of the other. You observe that the daughter plant has a slightly different leaf structure. With this information you can hypothesize that the daughter plant was produced through which propagation method? a. sexual propagation b. asexual propagation 2.In an experiment in which petroleum jelly is placed on the underside of some of the leaves of a plant, what would be the expected outcome? a. transpiration would increase b. photosynthesis would increase c. there would be no effect on the plant d. transpiration would decrease b. increase 3.For most grass seeds, how will additional light during germination affect germination rate? a. decrease c. not affect 250

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4.Greenhouses offer more control than crops grown in field conditions over which of the following variables? b. lack of fertility a. embryonic growth a. machinery costs b. environmental conditions c. labor d. all variables 5.Seeds that you planted several weeks ago still havent germinated. In reexamining your seeds you observe that pots containing your seeds were flooded with water. What factor is most likely the cause for the seeds not germinating? a. low temperature c. lack of moisture d. lack of oxygen 6.How does gibberellic acid affects seed germination rates? a. increasing the response to plant toxins b. increasing the concentration of soil moisture c. increasing cell division 7.Seed germination involves the action of enzymes which: a. convert starch into sugar b. convert starch into amino acids c. convert starch to gibberellic acid 8.Which part of a seed is actually a plant in an arrested state of development? a. endosperm b. plantlet c. embryo 9.What causes seed swelling at the beginning of germination? b. water intake c. cell division d. enzymatic activity 10. Which of the following leaf arrangements has the highest transpiration rate? a. alternate b. opposite c. whorled d. leaf arrangement does not affect transpiration rate. 251

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11. Why are wet, compacted soils likely to result in lower germination rates? a. increased oxygen b. increased water c. decreased oxygen 12. What is commonly the cause of salt buildup in soils? c. use of pesticides a. Arizona b. Tennessee b. many small roots 15. What would you expect for a plant that is grown in direct sun, given adequate amounts of fertilizer and water? b. use a lot of chemicals on his fields to dissolve the soil a. under-fertilization b. overwatering d. inadequate watering 13. In which of the following states is soil salinity of most concern? c. Kansas d. Ohio 14. Which of the following best describes the characteristics of a dicot plant? a. narrow leaves with parallel veins c. two seed leaves d. three or more leaves at each node a. evaporation to be low b. transpiration to be high c. photosynthesis to be low 16. When seeds are planted too deeply, why is germination rate reduced? a. a fungus often develops due to excessive moisture b. sunlight is not available c. seed rot occurs d. food reserves are used up before roots can begin nutrient uptake 17. A farmer lives in a salinity affected area. What would be the best strategy for him to get the most productive yields from his land? a. irrigate occasionally, especially when it is hot c. use moldboard plowing d. plant salt-tolerant plant varieties 252

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18. In general, as soil temperature decreases, what will happen to germination rate? a. is unaffected b. decreases c. increases 19. What is water loss through plant tissues called? a. dehydration b. evaporation c. transpiration c. flowers a. to incorporate nutrient solutions d. to replenish dry soils a. 49% d. 99% 20. Where does water loss in plant tissues primarily occur? a. leaves b. stems d. roots 21. When managing a greenhouse, how should you water? b. to keep soils wet c. to avoid extremes in water availability 22. Approximately what percentage of all water absorbed by a plants root system is given off through plant tissues? b. 67% c. 90% b. tissue thickness 23. As water is lost from plant tissues, differences in which variable creates a suction effect that pulls more water into the plant through the root system? a. osmotic pressure c. humidity d. air pressure 24. Plants lose their ______ as water content decreases in plant cells a. leaves b. vigor c. turgidity d. phloem 253

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25. Which of the following is NOT a component of the process of photosynthesis? a. nitrogen b. light c. carbon dioxide d. oxygen 26. Which plant has the highest rate of transpiration? a. a small plant in a bedroom b. a large plant in a garden c. a small plant in a garden d. a large plant on a porch 27. In general, what happens to the amount of water loss through the plant tissue as the temperature drops on a cool, fall day? a. decreases b. cycles up and down c. remains constant d. increases 28. On a warm, sunny day with a slight breeze, the loss of water through the plant tissues will be: a. increased by the breeze due to lower humidity around the plant tissues b. unaffected by the breeze c. decreased by the breeze due to higher humidity around the plant tissues d. increased by the breeze due to movement of the plant tissues 29. The loss of water through the tissues of most plants: a. occurs during lighted, warmer times of the day b. is unrelated to processes in the plant c. occurs at the same rate throughout the day and night d. occurs during the dark, cooler hours only 30. What occurs when water is lost through plant tissues at a faster rate than water can be absorbed by the root system? a. wilting b. growth c. symbiosis d. photosynthesis 31. What are the tiny pores through which water vapor escapes from the plant tissue called? a. micropores b. stomata c. macropores d. xylem 254

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32. What is formed by groups of cells that are alike in activity and structure? a. Nucleus b. Organ c. Tissue 33. What is the movement of water from greater concentration in the soil to lower concentration in the root is called? a. absorption b. osmosis c. intake 34. What is the process by which an organism provides its cells with oxygen is called? a. photosynthesis b. light reaction d. respiration 35. Some seeds must go through a period of cold temperatures before they will germinate. What is this process called? c. scarification 36. Which of the following provide the energy needed to power the Calvin cycle? c. photosynthesis and ATP 37. What happens to a plants transpiration rate as the amount of oxygen in the environment surrounding a plant decreases? c. increases c. transpiration a. stratification b. cold fusion d. dormination a. ATP, carbon dioxide, and oxygen b. NADPH and ATP d. respiration and RuBP a. decreases b. stays the same 38. Which of the following processes creates a pull that aids in the absorption of water by the roots? a. photosynthesis b. respiration c. transpiration d. cell division 255

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39. Which of the following is NOT a function of plant roots? a. anchor plants b. produce food c. absorb water and minerals d. store food c. cold germination test c. phloem b. style a. leaf, stem, root d. leaf, xylem, root 40. What is the standard industry test for determining seed viability? a. TZ test b. warm germination test d. excised embryo test 41. Which of the following conducts water up the stem and to the leaves? a. xylem b. roots 42. Why shouldnt germinating seeds come in contact with fertilizers? a. salt has a negative effect on water intake b. seed rot is a greater concern c. excessive growth will occur d. the fertilizer will dissolve too quickly 43. After fertilization, the ovary wall enlarges and forms which part of the plant? a. seed c. fruit 44. Why are well drained soils less likely to suffer from salt buildup? a. water moves rapidly downward through the soil, leaving salts on the soil surface b. water runoff is greater c. water moving downward through the soil carries salts with it d. water evaporates from the soil surface more quickly 45. Which of the following is NOT a cell organelle? a. vacuole b. stolon c. mitochondria d. nucleolus 46. Which of the following plant part lists are in the order in which water enters a plant? b. root, xylem, leaf c. root, phloem, leaf 256

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47. What would be the best way to determine the effect temperature has on transpiration? a. Place a plant in a heated room. Measure the time it takes the plant to become wilted. b. endosperm c. soil a. complex sugar c. oxygen 50. How does the process of osmosis aid in plant nutrient uptake? b. water and nutrients are absorbed by the roots until the nutrient concentration is high. c. water moves from a greater concentration in the soil to a lower concentration in the root. b. Place two plants inside a jar of water. Measure the temperature and the amount of water that is lost from the jar. c. Place two plants in two separate jars of water. Place them at two different temperatures and seal the top of the jars. Record the amount of water that is lost from the jar. 48. Where does a young seedling gains the food it needs until it is able to manufacturer its own? a. embryo 49. What is produced when water, carbon dioxide, and light energy are in the presence of a healthy green plant? b. starch a. water leaves the root until the pressure inside the root is less than the pressure outside the root 257

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APPENDIX E ANSWER KEY TO CONTENT KNOWLEDGE INSTRUMENTS Multiform Grid Answer Pretest Posttest D 1 4 1 B 3 40 C 4 3 D 5 5 C 6 6 D 7 16 A 8 7 C 9 8 B 10 18 B 11 9 C 15 44 B 16 15 A 19 A 20 20 D 21 21 D 22 22 B 23 31 A 24 23 C 25 24 B 26 26 27 A 28 28 A 29 29 A 30 30 C 31 32 B 32 33 A 33 25 A 34 34 A 35 35 B 36 36 B 37 48 A 38 37 A 2 C 12 11 D 13 12 A 14 13 17 42 D 18 17 C 19 A 27 258

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259 Answer Pretest Posttest 38 39 A 41 14 A 42 41 C 43 43 45 B 45 46 C 46 47 D 47 2 D 48 10 C 49 49 C 50 C 39 B 40 B 44 50

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260 APPENDIX F STUDENT DEMOGRAPHIC INFORMATION SHEET DIRECTIONS: Please complete the following information for all students in the Agriscience Foundations class. School ID: XX Section ID: X Total number of days lessons were taught: Student ID# Name a Grade National School Lunch Program b Ethnicity Gender Days Absent c 01 9 10 11 12 Does not participate Reduced lunch Free lunch Black Hispanic White Other Male Female 02 9 10 11 12 Does not participate Reduced lunch Free lunch Black Hispanic White Other Male Female 03 9 10 11 12 Does not participate Reduced lunch Free lunch Black Hispanic White Other Male Female 04 9 10 11 12 Does not participate Reduced lunch Free lunch Black Hispanic White Other Male Female 05 t participate anic Male 9 10 11 12 Does no Reduced lunch Free lunch Black Hisp White Other Female 06 9 anic Male 10 11 12 Does not participate Reduced lunch Free lunch Black Hisp White Other Female a The name column is included on this form for your schools use only. Please mark out the names of student when returning this form.. b This information will need to be obtained from your schools student services departmentThe number of days the student was absent when the lessons were being taught. c

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261 IRB APPROVAL APPENDIX G

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262 APPENDIX H INITIAL EMAIL TO PARTICIPATING TEACHERS Let me thank each of you again for agreeing to participate in the Agriscience Foundations project this fall. I just wanted to send out a quick e-mail to make sure the address that I have is correct and to provide you with some more introductory information. Please let me know your school's start date. That way I can make sure to get the permission forms to you prior to the start of school. Also, if you know a time that will work best for me to stop by your school to drop off the project supplies please let me know that as well (late July early August). I'm guessing we would need to schedule about two hours to visit about the project during my visit. Also, as soon as you know some firm numbers on your Agriscience Foundation class enrollment, let me know. Once I have that information, I can start to put together the packets for each school. As you recall, the lessons should take 4-6 weeks to complete in your class. All lessons are part of a plant germination unit. Please look at your course calendar and let me know when you would like to teach these lessons. The only time restrictions are that the lessons need to be taught in a solid block and completed no later than mid-November. There are a number of ways you can contact me. The easiest way is by e-mail. However, feel free to call me at any of the phone numbers listed below. E-mail: bmyers@ufl.edu Office: (352) 392-0502 ext. 223 Home: (352) 373-1773 Mobile: (352) 256-2457 Thank you again and please send me your school's start date, Agriscience Foundations enrolment numbers, and a preferred meeting time as soon as you can. I look forward to working with each of you on this project. Brian Brian E. Myers Agricultural Education and Communication Department University of Florida 310 Rolfs Hall / PO Box 110540 Gainesville, FL 32611-0540 (352) 392-0502 ext. 223 http://plaza.ufl.edu/bmyers/

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APPENDIX I OUTLINE FOR VIDEO TAPED TEACHER INSTRUCTIONS Section I: General Information (Same for all three versions) I. Consent letters A. Forms A, B, & C D. How long will it take? A. Student B. Parent/Guardian C. Teacher II. Student Demographics Sheet A. ID Number B. Days of Instruction C. Other information 1. Work with Student Services Department III. Content Knowledge Exams A. Forms A, B, & C B. Completing the answer sheets C. When to administer D. How long will it take? IV. Science Process Skill Test A. Forms A, B, & C B. Completing the answer sheets C. When to administer D. How long will it take? V. Attitude Toward Instruction Survey B. Completing the answer sheets C. When to administer 263

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264 VI. Audio Tapes A. What to record B. Who reviews the tapes C. Why? VII. Returning Materials A. Business reply envelops B. Band like items C. When Section II: Lesson Plans (Three different versions SM, PL, IL) II. Lesson Plan Format A. Objectives B. SPS 1. Worksheet F. Applications (Only for PL and IL versions) I. Description of assigned teaching technique C. Equipment, supplies, etc. D. Content 1. Transparencies 2. Handouts E. Review/summary 1. Lab sheets III. Suggested Teaching Calendar IV. Demonstration of lessons/labs A. Scientific Method (06.00) 1. LS: 06.00.PL or LS: 06.00.IL a. Teacher Instructions b. Student Handout B. Examining Plant Structures and Functions (06.01) 1. LS: 06.01.PL or LS: 06.01.IL a. Teacher Instructions b. Student Handout

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265 C. Determining the Importance of Photosynthesis and Respiration (06.02) 1. LS: 06.02.PL or LS: 06.02.IL a. Teacher Instructions b. Student Handout 1. LS: 06.03.A.PL or LS: 06.03.A.IL D. Propagating Plants Sexually (06.03) 2. LS: 06.03.B.PL or LS: 06.03.B.IL a. Teacher Instructions b. Student Handout Section III: Conclusion (Same for all three versions) I. Contact Information II. Conclusion and Thank you

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LIST OF REFERENCES Abbott, M. L., & Joireman, J. (2001). The relationship among achievement, low income, and ethnicity across six groups of Washington state students: Technical report #1. Lynnwood, WA: Seattle Pacific University. Agresti, A., & Finlay, B. (1997). Statistical methods for the social sciences (3rd ed.). Upper Saddle River, NJ: Prentice Hall. American Association for the Advancement of Science. (1990a). The liberal art of science: Agenda for action. Washington, DC: AAAS, Inc. American Association for the Advancement of Science. (1990b). Science for All Americans. New York: Oxford University Press. American Association for the Advancement of Science. (1993). Benchmarks for science literacy. New York: Oxford University Press. Anderson, L. W., & Krathwohl, D. R. (2001). A taxonomy for learning, teaching, and assessing: A revision of Blooms taxonomy of educational objectives. New York: Addison Wesley Longman, Inc. Argyris, C., & Schon, D. (1974). Theory in practice: Increasing professional effectiveness. San Francisco: Jossey-Bass. Argyris, C., & Schon, D. (1978). Organizational Learning: A theory of action perspective. Reading, MA: Addison-Wesley. Balschweid, M., & Thompson, G. (1999). Integrating science in agricultural education: Attitudes of Indiana agricultural science and business teachers. Paper presented at the 26th Annual National Agricultural Education Research Conference, Orlando, FL. Berliner, D. C. (1987). Knowledge is power. In B. V. Rosenshine (Ed.), Talks to teachers. New York: Random House. Blakey, D., Larvenz, K., McKee, M., & Thomas, R. (2000). Improving student performance through the use of active learning strategies. Unpublished Action research project, Saint Xavier University, Chicago, IL. 266

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267 Boone, H. N., Jr. (1988). Effects of approach to teaching on student achievement, retention, and attitude. Unpublished dissertation, The Ohio State University, Columbus. Boone, H. N., Jr, & Newcomb, L. H. (1990). Effects of approach to teaching on student achievement, retention, and attitude. Journal of Agricultural Education, 31(4), 9-14. Bransford, J. D., Brown, A. L., & Cocking, R. R. (2000). How people learn: Brain, mind, experience, and school. Washington, D.C.: National Academy Press. Briggs, K. C., & Myers, I. B. (1977). Myers-Briggs type indicator. Palo Alto: Consulting Psychologists Press. Burchfield, M. L., & Gifford, V. D. (1995). The effect of computer-assisted instruction on the science process skills of community college students. Paper presented at the Annual Meeting of the Mid-South Educational Research Association. Campbell, D. T., & Stanley, J. C. (1963). Experimental and quasi-experimental designs for research. Boston: Houghton Mifflin. Cano, J., & Garton, B. L. (1994a). The learning styles of agriculture preservice teachers as assessed by the MBTI. Journal of Agricultural Education, 35(1), 8-12. Buriak, P., & Osborne, E. W. (1996). Physical science applications in agriculture. Danville, IL: Interstate Publishers, Inc. Cano, J. (1999). The relationship between learning style, academic major, and academic performance of college students. Journal of Agricultural Education, 40(1), 30-37. Cano, J., & Garton, B. L. (1994b). The relationship between agriculture preservice teachers' learning styles and performance in a methods of teaching agriculture course. Journal of Agricultural Education, 35(2), 6-10. Chiappetta, E. L. (1997). Inquiry-based science. The Science Teacher, 22-26. Chiappetta, E. L., & Koballa, T. R., Jr. (2002). Science instruction in the middle and secondary schools (5th ed.). Upper Saddle River, N.J: Merrill Prentice Hall. Chiappetta, E. L., & Adams, A. D. (2004). Inquiry-based instruction. The Science Teacher, 71(2), 46-50. Chiasson, T. C., & Burnett, M. F. (2001). The influence of enrollment in agriscience courses on the science achievement of high school students. Journal of Agricultural Education, 42(1), 61-71. Chickering, A. (1977). Experience and learning: An introduction to experiential learning. New Rochelle, NY: Change Magazine Press.

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BIOGRAPHICAL SKETCH Brian Eugene Myers was born July 22, 1974, in Pittsfield, Illinois. Mr. Myers was raised on his familys farm in rural Pike County, Illinois. He graduated from Pittsfield High School in 1992. While attending high school, Mr. Myers was very active in 4-H and FFA. Mr. Myers received his Bachelor of Science (cum laude) degree in general agriculture with a specialization in agriculture education from Southern Illinois University in Carbondale in 1996. As part of his degree program, he completed his student teaching at Mt. Vernon Township High School in Mt. Vernon, Illinois, under the supervision of Mr. John Kabat. Upon graduating, Mr. Myers accepted a dual graduate assistantship from both the Agricultural Education and Mechanization and Plant and Soil Science Departments at Southern Illinois University at Carbondale. As part of his duties, Mr. Myers taught courses in agricultural education and the Introduction to Crop Science laboratory sections. Additionally, Mr. Myers was the advisor for the SIUC Collegiate FFA and as such worked closely with teachers in southern Illinois in planning several FFA events. Mr. Myers received his Master of Science degree in agricultural education and mechanization specializing in agricultural education in 1997. Following the completion of his M.S. degree, Mr. Myers accepted an agricultural education teaching position at Unity High School in Mendon, Illinois. While at Unity High School, Mr. Myers taught students in grades eight through twelve in many areas of 276

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277 agricultural education as well as Tech Prep courses. In addition to his duties as an agricultural educator, Mr. Myers was an active member of the community, serving on many boards and committees such as the Adams/Brown Cooperative Extension Administrative Board. Mr. Myers was a member of the Illinois Association of Vocational Agriculture Teachers, the National Association of Agricultural Educators, the National Science Teachers Association, Phi Delta Kappa, and numerous other educational organizations. His efforts as an agricultural education teacher and FFA advisor have been recognized by numerous organizations, including being named Illinois 1st runner up of the NAAE Outstanding Young Member award. Mr. Myers also worked as an educational consultant with the Center for Agricultural and Environmental Research and Training. Mr. Myers has conducted numerous professional development workshops for agricultural educators across the country in the areas of agriscience curriculum development and implementation. He has also authored major portions of the agricultural education curriculum in several states. In 2001, Mr. Myers accepted a graduate teaching and research assistantship with the Agricultural Education and Communication Department at the University of Florida and began work on a Ph.D. in agricultural education. Mr. Myers taught or assisted with numerous undergraduate and graduate courses in department as well as supervised student teachers. Additionally, he conducted numerous research studies in the area of agricultural education. Mr. Myers was married to Margaret Jahnke in July of 1997. They have a son, Timothy, born in July of 2000.