In-xla' -.—..-.M. a. u- . A M ».~-lu“x1 «nu ILC‘I ‘ Ella-$.15 LIBRARY Michigan State University This is to certify that the thesis entitled The Effect of Computer—Assisted Instruction and Laboratory Experimentation on the Learning of Photosynthesis and Respiration in High School Biology presented'by Marlo Dawn Wiltse has been accepted towards fulfillment of the requirements for MS (kgmehiLnLgndepartmental Biological Science (W Major professor Date /2 “(7 a1 03639 MS U is an Affirmative Action/Equal Opportunity Institution PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE JUN 4 ‘0 ZOE“; 6/01 c:/CIRC/DateDue.p65-p. 15 THE EFFECT OF COMPUTER-ASSISTED INSTRUCTION AND LABORATORY EXPERINIENTATION ON THE LEARNING OF PHOTOSYNTHESIS AND RESPIRATION IN HIGH SCHOOL BIOLOGY By Marlo Dawn Wiltse A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Division of Science and Mathematics Education 2002 Professor Merle Heidemann ABSTRACT THE EFFECT OF COMPUTER-ASSISTED INSTRUCTION AND LABORATORY EXPERIMENTATION ON THE LEARNING OF PHOTOSYNTHESIS AND RESPIRATION IN HIGH SCHOOL BIOLOGY By Marlo Dawn Wiltse This research is a study of the usefulness of computer tutorials and laboratory experimentation in a high school biology course to learn photosynthesis and respiration. The study was conducted to determine the effectiveness of providing content information through computer-assisted tutorials, and experimentation to increase understanding of the content in comparison to using lecture notes and practice worksheets. Fifty-three high school freshmen were the subjects in the study. Subjects interacted with ten computer tutorials and conducted five laboratory experiments pertaining to photosynthesis and respiration. Results of the activities as well as pre- and post-tests, final exams, and surveys were used to evaluate this study. This thesis is dedicated to my husband, Don, and my son, Hunter, for their unending support and patience throughout this process. It is also dedicated to my parents, Don and Nancy Santer, for always believing in me and helping me to believe in myself. iii ACKNOWLEDGEMENTS I would like to express my deepest gratitude to the following people for their personal and professional support: My husband, Don, for his advice and help with every aspect of this process. My mentors and friends at Charlotte High School. MSU personnel: Becky Murthum for always being kind and helpful, and Merle Heidemann, and Ken Nadler for being wonderful sources of ideas and answers. Helen Keefe for her guidance and the staff of the MSU Lite Lab for all of their support. My mother, Nancy Santer, for her constant assistance and support. The Towsley Foundation for their financial support of my education. My students for their cooperation during the study. iv Table of Contents List of Tables ................................................................................. vii Introduction and Literature Review ......................................................... 1 Demographics of Classroom ....................................................... 9 Scientific Principles Taught in Unit ............................................... 10 Implementation of Unit ...................................................................... 12 Tools Used to Teach Unit .......................................................... 14 Analysis of Unit Plan and Activities .............................................. 18 Unit Evaluation ................................................................................ 22 Calorimeter Lab............ .......................................................... 22 Chromatography Lab ................................................................ 23 Photosynthesis Lab .................................................................. 24 Photosynthesis & Respiration Lab ................................................. 24 Metabolizing Food Lab .............................................................. 26 Interactive Tutorials .................................................................. 27 Pre- and Post-Tests .................................................................. 28 Final Exam ............................................................................ 37 Survey ................................................................................. 40 Discussion ...................................................................................... 41 Appendix A: Laboratory Experiments A-l: Photosynthesis Lab ............................................................. 49 A-2: Photosynthesis & Respiration Lab .......................................... 54 A-3: Calorimeter Lab ................................................................ 57 A-4: Chromatography Lab .......................................................... 62 A-5: Metabolizing Food Lab ....................................................... 67 Appendix B: Guided Worksheets B-l: (2-1) Overview .................................................................. 73 B-2: (2-2) Absorbing Light Energy ................................................ 75 3-3: (2-3) Electron Transport Chain ............................................... 77 B-4: (24) Making ATP ............................................................. 79 B-S: (2-5) Calvin cycle ........................... '.'. ................................. 81 B-6: (2-6) Regulation ................................................................ 83 8-7: (3—2) Glycolysis ................................................................ 85 B-8: (3-3) Krebs cycle ............................................................... 87 B-9: (3-4) Electron Transport Chain ............................................... 89 Appendix C: Assessment Tools & Rubrics C-l: 10—Question Free-Response Pre-Test and Post-Test ...................... 91 C-2: Rubric for IO-Question Free-Response Pre-Test and Post-Test ......... 92 C-3: Concept Map Pre-Test and Post-Test ....................................... 93 C-4: Rubric for Concept Map Pre-Test and Post-Test ........................... 94 05: Survey ........................................................................... 95 C-6: CP Bio Exam 2: Photosynthesis & Respiration Questions only... ......96 C-7: Rubric for CP Bio Exam 2: Photosynthesis & Respiration Questions only ................................................................. 102 C-8: Consent Form .................................................................. 103 References .................................................................................... 104 vi List of Tables Table 1: Lesson plan used in research ...................................................... 13 Table 2: 10—question free response pre- and post-test .................................... 29 Table 3: Concept map pre- and post-test ................................................... 29 Table 4: Final exam multiple-choice photosynthesis & respiration questions. . . . .....38 Table 5: Final exam completion photosynthesis & respiration questions .............. 39 Table 6: Student survey results .............................................................. 4O vii Introduction and Literature Review Biology is a course offered at all national high schools and taken by a large number of students enrolled in US. high schools. This course can be a difficult one, requiring understanding of abstract concepts and a large amount of new vocabulary. The number of students failing is high, especially when students get less attention due to large classes, lab facilities and equipment are insufficient, and requirements force students to take the course (Hounshell and Hill, 1989). Many concepts in biology are perplexing to secondary students but few are as daunting as those related to photosynthesis and respiration. There are misconceptions, misunderstandings, and difficulties, such as the concept that plants conduct respiration, that students at all levels of education have with the learning of photosynthesis and respiration. Because of this, the focus of this study was to use new methods of instructional delivery that might overcome the hurdles of this topic. Since computers are capable of doing so many tasks to enhance education, such as provide animations of processes, one of the elements I thought would improve the delivery of information was computer-assisted instruction in the form of interactive tutorials. The computer is useful for the role of tutor, but few studies have been done to determine its effectiveness in this realm (Ybarrondo, 1984 and Bennett, 1999). It seems that with the capabilities of computers today, there could be much benefit to using the computer for dynamic illustrations of processes. Software that could give instruction on complicated processes and include impelling graphics and audio, certainly has the potential to be enriching to a high school science classroom. However, there are doubts as to how useful computers can be as a learning tool (Jenkins, 1993). Some (Cuffaro, 1984) believe that what computers offer, like flashy pictures and sound, and animated objects on a screen are not representative of the world. On the other hand, the technological world now requires a student to have knowledge of computers and even be “savvy” when it comes to many software and hardware elements. The more capable they are in these areas, they better prepared they should be for future education or career (Matray and Proulx, 1995). Computer capabilities changed and improved dramatically in the last several years and continue to change, enabling more computer use in classrooms since there is more software and capability for use. However, the use of computers should be limited only to what is truly effective and not used just for the mere desire to use new technologies. As Lesgold (2000) has suggested, there are times when computers should be used, and when they should not. They should contribute to learning without becoming a curricular goal. Teachers commonly observe two problems students have with traditional written instruction. It is difficult to understand complicated processes with only simple pictures as illustrations, and students have trouble paying attention and focusing for more than a short period of time. Students‘complain that notes are boring and they get distracted or lose focus. A computer program could capture a student’s attention with bright colors, movement, and exciting sounds. The teenager of the new high-tech world is used to seeing lots of graphics with bright colors, loud noises and sophisticated animation. So, it would seem that most students of today would benefit from computer-assisted instruction. Several issues are important to consider when determining styles of teaching. One of these issues is level of student ability. Students of varying levels of ability are usually placed together in classes. Even when classes are ability based, there is some variation of aptitude within the students in the class. Students of low ability or interest often tend to be motivated and/or engaged by more tactual and stimulating methods. Studies involving computer usage in schools have shown that the “low-ability” students gain the most (Savenye & Strand, 1989 and Bender, 1996). Computers offer the advantage of hand contact in a motivating system. Secondly, learning styles can make a large difference in the performance and assimilation of information. Only recently have educators begun to recognize that the way in which students learn is a significant aspect to consider in implementing improvements in education (Geisert and Dunn, 1990). Students better suited for auditory learning will perform well under circumstances where listening is the key, such as during lectures. Others responding to methods such as visual, where seeing illustrations or images is helpful; tactile, needing the sense of touch to integrate information; or kinesthetic, which involves the use of body movement, will perform better using those learning styles. Computer use could meet the learning style needs of many students. Computers can be auditory, visual, tactile, and depending upon use, kinesthetic. Software programs usually involve some form of narration and often have stimulating graphics, meeting the needs of auditory and visual learners, respectively. Operation of a mouse and/or keyboard is usually required for computer use, therefore benefiting the tactile learners. Computers can be kinesthetic when students are asked to come to the computer and perform a simulation of a task or use the mouse. There are other beneficial reasons for using computers in classrooms. Studies have shown that self-esteem can be enhanced by computer use in classes. Morse (1991) found that lower achieving students have increased interest in science when their curriculum includes the use of computers. While using a computer in class, students may feel less tension from perceived embarrassment and disapproval. If students feel better about themselves, they will often be more focused, attentive, and participate which may lead to more learning and better performance (Robertson, et. al, 1987 and McMahon, 1999). Another element that makes a computer a useful classroom tool is its ability to increase learner control. Learner control can be described as “the degree to which a learner can direct his or her own learning process” (Amone, et. al, 1991). If students are able to direct their own learning (proceeding at their own pace, reviewing when needed, utilizing vocabulary banks and additional graphic options, etc.) they are more likely to be successful. By using assessments embedded in the program, students would be able to make sure they understood a topic before moving on and getting confused, and they could return to specific areas on which they felt they needed more practice. However, many students lack the self-direction and motivation needed to keep on task and take advantage of all the capabilities of the computer in order to maximize learning. Steinberg (1989) indicates that beginning level students in a particular subject area may lack the skills to effectively control their learning of general instructional materials. Students may be able to take advantage of some of the aspects of learner control if they have the additional direction of a teacher to guide them through the process. Also, a teacher being available and assisting in the execution of a computer program is helpful since sometimes information needs to be explained in a different way than is provided in the software. If the computer provides the main body of information, including review and reinforcement strategies, the teacher has more availability for meaningful time with students in areas that are less clear (Lu, et. al, 1997). Students who have more control over their learning tend to have a better attitude about the learning, which will lead to better performance. When considering the attitudes of students, the consequence of learner control has been a more optimistic feeling toward learning. (W indelspecht, 2001). The final element that makes computer use in classrooms beneficial is its interactive capabilities (Harper, et al., 2000). The computer can provide information for reading and graphic illustrations to watch and can furnish feedback to help determine what is right and wrong, and where additional learning is needed. It can analyze an answer and provide feedback about what was done incorrectly and hints as to how it can be corrected without just giving the answer. There are some important aspects that determine if software is effectively interactive. They are immediacy of response, non- sequential access of information, adaptability, and feedback (Borsook, 1991). These elements are important when deciding if software has the desired interactivity. A response shouldn’t take so long that the user has forgotten the question. Information should be provided in many sequences to fit the needs of the individual students. Otherwise, a student may need to return to another topic or skip around and may be frustrated by the inability to do so. The software should be able to adapt to the student or to the needs of the topic. Finally if the software does not provide feedback, it has very little use in the classroom, since it is only a textbook on a computer. After information has been dispensed to students, with or without computer-aided instruction, the next step is to make it meaningful to them in ways that they will comprehend and retain. A method thought to be beneficial in the teaching of the sciences is laboratory experimentation. Tobin (1990) believes that laboratory activities allow students to engage in a method of learning by performing activities that enable them to “construct knowledge.” von Glasersfeld (1987) suggests that the construction of knowledge occurs through two processes, assimilation and accommodation. Assimilation involves taking an activity one has experienced and incorporating it into their cognitive structures. Accommodation involves applying what one has learned from the experience to new situations. Laboratory experimentation is thought to do just that, give a student an experience that they can use to relate to the concepts learned. Experimentation allows them to be more actively involved in the lesson and in their learning, it requires them to follow directions to execute the activity, and it demands their thought and problem- solving skills. Tobin (1990) also notes that problem solving is favored in science instruction because learners can be engaged in real-life experiences from the scientific realm. Students make observations about what has occurred in the experiment, analyze their data to determine what it means, and reach a conclusion about the problem. If students are able to extrapolate meaning from the laboratory data and reach a logical conclusion, this should indicate they understand the concepts presented. Since laboratory experimentation appears to be such an effective learning tool, it was used in this study to help students construct knowledge about photosynthesis and respiration. However, there are problems with laboratory experiments. According to a study done by Lehman (1989), teachers felt laboratory activities were beneficial to reinforce concepts and principles presented in lectures. Students in this study agreed with this assessment but also felt that laboratories were difficult to comprehend, confusing, and the results often had no meaning. These problems are especially relevant when designing the materials for photosynthesis and respiration. These topics consist of difficult concepts, such as understanding the activity of an electron in the electron transport chain. In order to engage in experiments, students must have a deep comprehension of the subject. Even when they have covered the information, and ideally understand it, the processes occurring are at a molecular level and are impossible to see directly. Therefore, students are confused by the purpose and expectations of the lab exercise. With this in mind, this study was undertaken to design and/or modify laboratory experiments that would teach the scientific principles of photosynthesis and respiration in a way that students could comprehend. Some of the laboratory activities used are standard ones, like chromatography to separate the pigments of a plant leaf. Others are modified versions of standard labs, such as spectrophotometry using a computer and interface with a colorimeter probe. Still others were developed to enhance students’ scientific experimentation skills. Lab simulations can be done in replacement of traditional labs. Magin and Reizes ( 1990) propose that simulated experiments can provide the flexibility to change parameters in a way conventional laboratory work cannot, therefore expanding learning outcomes. Sometimes labs are difficult to prepare, set up, or conduct and lab simulations can be a good compromise. Students can “complete” a laboratory experiment, gaining the experience and knowledge of the lab and its outcomes without actually having to do the steps. However, computer availability on a large classroom scale is a problem and software must be found that is affordable and effective in achieving the desired outcomes. Because of the need to do labs and to incorporate computers, computer-based probes were used in this study for several activities as a tool to gather data. In two laboratory experiments, the computer was used in connection with an interface where sensors could “read” information and provide data. Students were conducting the experiment and taking data from the computer. One of the lab activities could not have been done in any other way. In summary, this unit was designed to determine if computer-assisted instruction and the use of laboratory experimentation are beneficial in the teaching of photosynthesis and respiration to high school biology students. Demographics of Classroom Students participating in this study were freshman level students in a college preparatory biology course. There were two sections of the class, 1St block and 3rd block. The school’s schedule is a 4 x 4 block, which means the students have four 90-minute classes each day for 18 weeks. After 18 weeks, they begin new classes, completing eight different courses each year. A total of 53 students, 20 females and 33 males, participated in the study. The gender ratio was atypical; many other science classes contain closer male-female ratios. Ethnic diversity in the school is low. All of the students agreed to allow their data to be used for research and returned their consent form [Appendix G8]. The two groups were fairly typical of freshman biology classes, made up of varying levels of students. Biology is a required course for all freshmen. However, there are two levels of the course, general biological science and college preparatory biology. Students and their parents make their own choices as to which class to take. Therefore, classes contain a diverse population of students at different levels. The school is a suburban/rural high school of approximately 1100 students. Small business owners, factory workers, and farmers make up a large part of the community. Scientific Principles Taught in Unit The purpose of this unit was to teach the concepts of photosynthesis and respiration. The intent was for the students to learn the processes at a very basic cellular and molecular level, as well as to understand the relationship between them. The unit began with discussion about autotrophs, organisms that can use energy from sunlight or inorganic compounds and produce organic compounds, and heterotrophs, organisms that depend on other sources for their energy requirements. Students were reminded that energy is stored in the bonds of compounds and by breaking those bonds the energy can be released to do cellular work. I wanted the students to understand the relationship between photosynthesis and respiration as students saw that autotrophs are at the base of the food chain and are relied upon by all living things. Students learned about the structure of the chloroplast, including the interior features. Students were introduced to the molecules that make up the photosystems and electron transport chains but were not expected to know them in detail. They were expected to understand photolysis; the electrons increase in energy due to light, the activity of the electrons and protons in the electron transport chain, and subsequent formation of ATP and NADPH. Also, they were responsible for knowing the Calvin cycle: what reactants were necessary for it to occur, what the main purpose of it was, and the end products. Students learned that the first step was glycolysis, where a glucose molecule was broken down into 2 pyruvic acid molecules, using 2 ATP and producing 4 ATP with a net gain of 2. They were informed about the function of NAD+ as an electron acceptor in glycolysis. They were given an overview of the Krebs cycle, held responsible for knowing the main purpose, the 10 reactants that went in and the products that came out. They learned about the electron transport chain, the electron carriers that brought electrons to it, how ATP was produced via chemiosmosis, and the final electron acceptor. Finally, they were educated in the alternative processes that take place under certain conditions, anaerobic respiration and fermentation. They were instructed that anaerobic respiration was a process similar to aerobic respiration but differing in the electron acceptor, using an alternate acceptor rather than oxygen. Both types of fermentation, lactic acid and alcoholic, were taught including the end products and the purpose of the processes. Students were responsible for knowing where each of the processes took place inside the cell. 11 Implementation of Unit Students that participated in this study were in a college preparatory biology course. Freshman coming into the high school from our middle school have not had instruction in the life sciences since the sixth grade. Student learning, in terms of their responses and overall performance, rather than average scores, determined effectiveness for all assignments except tests. The photosynthesis and respiration unit is chapter five in the book, Biology, Principles and Explorations by Raven and Johnson (2001). Therefore, the school year started with chapters on biology themes, scientific method, cells, and cell membranes. Prior to starting this unit, students were familiar with the basic structures and functions of the cell organelles. Units were each taught in a similar way, starting with a concept map about the topic and an introductory assignment to familiarize the students with the basic ideas of the topic. The material was then taught through various methods, including written notes, guided notes (where most of the material is provided but there are missing pieces that students must fill in as it is covered), group activities, inquiry activities, model building, and laboratory experiments. Toward the end of each unit, a quiz was given to assess their understanding of the material before the final test, and a class review session took place the day before the test. Finally, a unit test was given covering the entire unit, consisting of multiple choice, completion, and constructed- response questions. When students finished the test, they would turn it in and pick up the concept map and introductory assignment for the next chapter. This would be completed before the start of class the next day. Students were allowed to use the book and help each other to complete these assignments. 12 Table 1 Lesson plan used in research Day Topic Exercises & Assignments 1 Pre-test on photosynthesis & respiration *concept map * lO-question exam 2 Autotrophs, heterotrophs, food chain, Notes energy *Calorimeter lab HW: food chain worksheet 3 Begin photosynthesis Go over homework *Follow up on Calorimeter lab *Tutorial 2-1 Overview of photosynthesis HW: 5-1 Directed Reading Worksheet 4 Light Absorption & pigments *Tutorial 2-2 Absorbing Light *Chromatography Lab HW: 5-2 Directed Reading Wksht 5 Electron Transport Chain *Chromatography Lab follow-up *Tut. 2-3 Electron Transport Chain HW: Photosynthesis Worksheet 6 ATP Production *Tutorial 2-4 Making ATP *Photosynthesis Lab HW: Photosynthesis Worksheet 7 Calvin Cycle *Follow-up on Photosynthesis Lab *Tutorial 2-5 Calvin Cycle HW: Photosynthesis Review Wksht 8 Regulation of photosynthesis & review *Tut. 2-6 Regulating photosynthesis Photosynthesis quiz 9 Glycolysis Return quiz, discuss *Tutorial 3-2 Glycolysis HW: Respiration worksheet 10 Krebs cycle *Tutorial 3-3 Krebs cycle Respiration worksheet 11 Electron Transport Chain *Tut. 3-4 Electron Transport Chain *Photosynthesis and Respiration Lab 12 Anaerobic respiration & fermentation Notes *Metabolizing Food Lab 13 Anaerobic respiration & fermentation, *Metabolizing Food Lab results, review follow-up Unit review 14 Unit test Unit test *Concept map * IO-question exam 15 Survey of unit *survey * Denotes activities created for this research unit 13 Tools Used to Teach Unit Five labs were used in this unit to help students understand the concepts. Two of the labs, Photosynthesis Lab [Appendix A-l], and Photosynthesis and Respiration Lab [Appendix A-2], used a computer with an interface and probes. The other three labs, Calorimeter Lab [Appendix A-3], Chromatography Lab [Appendix A-4], and Metabolizing Food Lab [Appendix A-5] used standard laboratory equipment. Our book, Biology Principles and Explorations, by Raven and Johnson (2001), produced the tutorials used in this unit. They consisted of ten separate sections covering the topics of photosynthesis and respiration. The interactive tutorials were used as a way of getting information to students in a form that would be more visual and interactive than traditional lecture and note format. Since photosynthesis and respiration are complicated processes with a great deal of action at a cellular and molecular level, it was believed that using the computer tutorials would achieve multiple goals, such as allowing them to keep focused while taking notes but not becoming bored due to writing out lengthy notes as well as providing stimulating animations about the material. Guided worksheets [Appendices B-l through B-9] enabled students to process the majority of information necessary so as to focus on the understanding of the material and required them to remain attentive in order to complete the notes. Also, the tutorials consisted of dynamic visuals, which clearly illustrated the processes. This was also expected to help maintain student attention and interest, since they were able to watch the process. There was extensive narration of the visuals, explaining what was occurring as it was shown. There were two parts of interactive review of the material from each section. For example, when learning about the effects of light intensity or concentration of carbon 14 dioxide, students could increase or decrease the levels of these items to see the changes in the growth of a plant. These enabled students to answer questions using the visual models to check their understanding. After correctly completing the interactive sections, the students then answered four to six questions pertaining directly to the topic covered, forcing them to show their understanding or once again review the information until they reached an answer. While students were answering the review questions, I would hand out the papers for the next activity. This was an effective use of time. After completing the worksheet together, students could determine their own understanding of the topic before moving on and forgetting or getting confused. It was a valuable summary of the lesson There were two different forms of assessment used as pre- and post-test for the unit.. A 10—question free response test [Appendix C-1] and a concept map test [Appendix C-3] were used. Both were given as pre-tests before the unit was started, and as post- tests when the unit was finished. Concept maps are a way of organizing information that illustrates the relationships between the ideas. A blank concept map, containing boxes linked with each other through connecting words or phrases, was given to students. Students were given the map prior to starting the unit and their answers indicated what they already knew about the topic. This helped me determine how best to teach the concepts as well as what things students could spend less time on due to their prior understanding, or things that will require more time due to misconceptions. When tested after having studied the material, students again filled in the concept map to show their learning. 15 The free response test format was a test with 10 open-ended questions. It was used because it enabled the use of questions the concept map couldn’t accommodate. If all the concepts had been included in the concept map, it could not have been only one page and it would have been too complicated. The concept map covered the big picture ideas with a few specific ideas and the free response test covered some main ideas but many more specific ideas. In the evaluation of the pre- and post-test assessments, concept map scores may be higher in many cases. This was due to the fact that the concept map used connecting words, which gave an indication of what was required, as well as Subsequent boxes that help one understand the intention of the question. In some ways, this made the concept map easier, since it provided prompts. Another assessment for this unit was the Unit 5 test. It consisted of traditional multiple-choice questions, completion questions, and free response questions. This test was not developed for this research unit and was not given as a pre-test, since it required very specific knowledge, such as the names of the electron carriers and the products of intermediate steps, that students could not have known. Therefore, the unit test was not analyzed by this study. A survey [Appendix C—5] was given to students to rate the different activities included in this unit. The activities were rated on their helpfulness in understanding the material and how they compared to other methods used in this class. Activities were rated on a scale of 1-5, 5 being the most helpful and 1 the least. Students completed the survey the day after the unit test. Survey results are presented in Table 6. l6 At the end of the 9-week term, six weeks after this unit was studied, a final exam was given. It was a 120-question test, with questions on photosynthesis and respiration, the cell cycle, meiosis, genetics, DNA, RNA, evolution, and classification. The test consisted of multiple choice and short answer questions. There were 29 questions [Appendix C-6] related to photosynthesis and respiration. The results for this portion of the test are given in Tables 4 and 5. 17 Analysis of Unit Plan and Activities Day one - To begin this unit, students picked up the concept map and 10-question pre- test. However, they were told that they could not use their book or help each other in any way. They were told that these items were to be the pre-test for this research unit and would serve as baseline for what prior knowledge they had. They were counted as regular assignments, each worth 15 points of their grade. Day two - We started with a review of autotrophs and heterotrophs, and brief notes about the food chain. Following the notes, students began the Calorimeter Lab. The Calorimeter Lab was used in the beginning of the unit to get students to begin thinking about the energy that is stored in food. Students had previously learned that the bonds between elements in compounds store energy. Once the temperature increase and the mass of food burned were determined, the student could determine how much energy was given off per gram of food. A discussion then ensued about the source of the energy, and how the energy was transferred to the water. In this lab, students were asked to consider the food chain, where energy ultimately comes from, and each step the energy passes through. Day three - We went over the homework and Calorimeter Lab from day two. The lab was lengthy and follow up on the lab had not been possible the day before. Also, some of the questions on the homework assignment were difficult and students needed guidance. This was followed by the first tutorial, Overview of Photosynthesis. Day four — We completed the second tutorial, Absorbing Light, which explained how a plant takes in light from the sun. The Chromatography Lab followed this. The Chromatography Lab enabled students to separate the various pigments contained in a 18 leaf. Students learned that photosynthesis takes place in a leaf, inside the chloroplasts. Discussions about pigments and their functions were discussed so students would understand that pigments not only give color to a plant, but also absorb certain wavelengths of light energy. By separating the pigments of a spinach leaf, the students were able to see the different colors of pigments contained in a green leaf and discuss their functions. Day five — This day began with discussion about the Chromatography Lab from day four. Students often finish lab work at different times, making follow up for the lab difficult to do on the day of the lab. Tutorial three, Electron Transport Chain, was next, followed by a photosynthesis worksheet. Day six - Tutorial 2-4, Making ATP, started the day, which ended with the Photosynthesis Lab. The purpose of this lab was to simulate the light reactions of photosynthesis so students could indirectly observe the oxidation-reduction reaction that occurs. DCPIP, an electron acceptor that is blue and turns clear as it is reduced, was used to simulate the nicotinamide adenine dinucleotide phosphate (NADPH) in plants. As the chlorophyll molecules absorb light energy, the DCPIP is reduced and turns clear. After executing this lab, students should have a better understanding of the function of NADPH and light in photosynthesis. Day seven - Discussion about the Photosynthesis Lab started the class. Tutorial 2-5, Calvin Cycle, followed the lab with students beginning their homework worksheet in class. 19 Day eight - This day brought the last photosynthesis tutorial, Regulating Photosynthesis, which discusses the factors that affect photosynthesis, like C02, temperature, and light intensity. Next were an oral review of photosynthesis, and a quiz of the topic. Day nine — To begin, quizzes were returned to students and discussed. The second respiration tutorial, Glycolysis, was completed (the first tutorial on respiration was an overview and was skipped due to time constraints and an avoidance of redundancy.) Day ten — The next tutorial 3-3, The Krebs cycle, was covered. A little time was taken to clear up some misunderstandings and make sure there were no questions before moving on. Students finished the hour by beginning their homework worksheet. Day eleven - Tutorial 3-4, Electron Transport Chain, was next followed by the Photosynthesis and Respiration Lab. The purpose of this lab was for students to compare the products of these two processes. This lab was done with a computer, CO2 and 02 probes. If students could correctly predict whether 02 and CO2 levels would increase or decrease under each condition, then they could show an understanding of these processes. Another benefit to this lab was that students could observe the relationship between these processes, since 02 was being taken in by respiration while being released by photosynthesis, and vice-versa for CO2. Day twelve - We began with previously prepared notes on anaerobic respiration and fermentation. The Metabolizing Food Lab followed this. This lab was developed to help students understand the three types of metabolism used by living things. Students able to analyze the results of the lab and determine which type of metabolism each organism used would indicate an understanding of the information. This lab was conducted on a Friday so the weekend allowed time for growth to occur. 20 Day thirteen - This day began with checking the results of the Metabolizing Food Lab and analyzing the data. Some discussion took place about the results. The rest of the time was spent reviewing the entire chapter for the unit test to take place the next day. Day fourteen — Students finished the unit test, which included multiple choice questions, completion and constructed response questions. It required a great deal of knowledge on details of both photosynthesis and respiration. Students were also given the same concept map and lO-question assessment given for the pre-test Day fifteen — Students completed the survey about the research unit that was conducted for this chapter. 6 weeks later - Given on the last day of the class, 6 weeks after finishing the photosynthesis and respiration unit, was the final 9-week exam. 21 Unit Evaluation Each of the tools used to teach this unit are analyzed in this section, beginning with the five labs in the order in which they were conducted in class. Following the evaluation of the labs are the tutorials, pre-and post-tests, survey, and exam. Each tool will be evaluated using the student scores, responses, and survey comments and data. Survey results [Table 6] are calculated in percentages, based upon high scores (4-5), average scores (3) and low scores (1-2). There are two categories of survey responses: how much the activity helped the student understand the material, and how it compared with other methods used in class. Calorimeter Lab This lab was difficult for the students. Many had problems executing the lab without error. Although I expected most of the students come into the class with a fair mathematics background, their mathematical problem-solving skills in this area were poor. We did not have a thorough discussion about how to do the math part of this lab because it seemed self-explanatory with the directions provided. But students found themselves confused and frustrated about how to do the math and answer the questions. These students have not had any physical science and were unfamiliar with the energy computations. The lab analysis questions were inappropriate for this level of student, so although student scores averaged 92%, the responses were incomplete, therefore giving little indication of the student’s understanding of the information. Through oral discussion, students showed that they did understand the basic concepts that the lab was meant to convey, such as the presence of energy in food, the source of the energy, and the 22 food chain. When students were asked if they thought this lab helped them understand the material, 49% rated it 4—5. Twenty seven % rated this lab a 3, and 24% of students rated it 1-2. This lab was, therefore, the 2nd highest rated lab in helping students understand. However, student comments showed that they liked it mostly because they enjoyed burning things. This might explain the fact that, on the survey, it had the lowest percentage of 4-5 ratings for helping more than other ways. It had the highest percentage of 3’5, with 45%, and one of the lowest l-2 scores, with 33%. This indicates that, although they didn’t find it as useful as other ways, they didn’t feel it was worthless as a learning tool. Chromatography Lab Students enjoyed this lab and were amazed at the colors separated from green spinach extract. The colors migrated up the paper very quickly and the students were able to measure the lines from each pigment compared to the solvent front and compute Rf values. The Rf values meant very little to them, but seeing the pigments separated out was amazing to them. Some students felt this lab was not helpful because in one class, the solvent used was not working properly, so results were poor. A new solvent was made but with little time to redo the lab, so some groups of students had incomplete data. The analysis questions in this lab were adequate, extracting from students the intended information. They understood that a green leaf contained much more than just green color; other colors of pigments were there also. It helped them in comprehending the idea of light and the colors light contains and how plants use the light. There were class discussions about why different plants have various colors of leaves and flowers, why the 23 colors change at certain times of the year, and how those colors can be used for other reasons. Students scored 96% on the questions, and their answers indicated an understanding of the material. 0n the survey, 43% of ratings were 4-5, and 31% were 1- 2 for help in understanding the material. This lab was rated 3rd in helping more than other ways, with 29% 4-5’s, but had the highest percentage of 1-2’s, with 51%. Photosynthesis Lab Students found this lab challenging. First of all, the school only had 6 colorimeters for use. Students were rotated through this lab over a two-day period in groups of two. The lab was somewhat lengthy, so time was an issue. Scores averaged 72%, which was low for a lab. A majority of the students that got low scores did so because they never answered the analysis questions. Based on oral discussion with the classes, it seemed that to they understood the lab and what it meant to show them about photosynthesis. The lab needs to be improved to shorten the time and develop questions that further analyze the students’ understanding of the information. This lab received ratings of 45% 4—5’s, which is the 3rd highest in helping understand material. It also had the 3rd lowest percentage of 1-2 ratings. In the category of helping more than other ways, it ranked 2'”, with 31% 4-5’s (equal to the highest rated lab), 29% 3’3 and 41% l-2’s. Photosynthesis & Respiration Lab This lab was performed after students had learned about both photosynthesis and aerobic respiration. At the start of the lab, students were asked to answer questions about what processes plants carry out, the mechanisms of these processes, and make 24 predictions about the levels of 02 and C02 under varying conditions. Because there was not enough equipment for the students to do the lab themselves, the lab was set up and performed for the students. The procedure was explained to them but the directions meant little to them without actually executing the steps. By the time they finished the pre-lab, data was collected and ready to record. Students commented that they understood the principles of the lab and were able to answerthe analysis questions adequately. However, they noted that they felt doing the lab as a demonstration was less meaningful to them than if they had done it themselves. 0n the pre-lab questions, students scored 77% on the 9 questions. About half of the questions answered incorrectly were due to students not even attempting to answer the questions. 0n the post-lab questions, students scored 64%. However, even though the scores were lower, the number of students getting all the answers correct was higher. There were equal numbers of students that didn’t attempt to answer the questions as that answered them all correctly, which lowers the average. The reason so many questions were left unanswered is that these questions were thought provoking, requiring reasoning and explanation. Students didn’t want to bother with that much work. The motivation to understand the lab was decreased when it was set up for them. This lab received the lowest ratings regarding its usefulness in helping understand the material and the comments all had to do with the fact that the students did not do the lab and didn’t find it useful just to see the end result. They also rated it one of the lowest in comparison to other methods. 25 Metabolizing Food Lab Students received information about the three types of metabolism before proceeding with the lab. The lab was performed and data recorded regarding the growth of the organisms in the culture tubes. Even though they had learned the three types of metabolism, and there had been discussion about them before the lab, there was still much confusion about what the data meant and how to interpret it. Further discussion ensued regarding the types of metabolism and what data would lead to each conclusion. After the discussion, students answered the laboratory questions and scored 86 percent on the questions about the types of respiration in general, which indicated that they understood the concepts. However, their responses to the specific type of metabolism conducted by the organisms were only 72% correct. This indicated that, although they understood that there were different kinds of metabolism, determining which type was used based on data collected from the lab perplexed them. The survey data showed that this lab received 49% 4-5’s, and only 22% 1-2’s, which is the highest rated lab for helping understand material. It was also rated the highest in helping more than other ways used, with 31% 4-5’s, 37% 3’5 and 33% l-2’s. Some of the comments made about the lab in the surveys were “cool to see growth of organisms in the tubes” and “helped understand respiration.” Since respiration occurs at a molecular level, it is difficult for students to envision the process. This lab made the concept more visual since they were able to see the result of the metabolism, signified by the growth of organisms. 26 Interactive Tutorials Ten tutorials were used in this unit, and guided worksheets were completed for each one. Students generally received the maximum amount of points for the guided worksheet, since the material was covered together in class with oral discussion about the topics throughout each one. The other main method of dispensing information to students was written notes. These included hand-drawn pictures by the teacher, prepared overheads, use of models, and demonstrations. 0n the survey for the category of tutorials helping understand material, 69% of ratings were 4-5’s, 22% were3’s, and 8% were 1- 2’s. A majority of students felt that this learning tool was useful. The ratings for written notes were 63% 4-5’s, 22% 3’5, and 14% l-2’s. Students felt that the tutorials were more helpful in understanding material, but most of those students also felt that notes were helpful. There is a smaller difference in the percentages for helping more than other ways used, with tutorials rating 45% 4-5’5, and written notes at 43%. This small difference is offset by the fact that only 33% of scores for tutorials were a 3 while notes received 39%. Tutorials were rated at 1—2 22%, with notes being rated 1-2 18%. It was interesting to see that some students felt very strongly about one method or the other. Some students rated the tutorials very high and the written notes very low, even commenting that they hated writing notes, notes were boring or hard to understand. They indicated that they liked the tutorials because they had good graphics to illustrate processes, and they were able to listen instead of just writing all the time. It was often the lower-scoring students that preferred the tutorials over written notes. Other students were the opposite, rating the written notes very high and tutorials very low. Some remarked that the tutorials were too fast, hard to understand, or boring. Some said that they lost 27 focus during the tutorial because without writing anything, they weren’t forced to pay attention. Still other students rated the two techniques as fairly equal, each having advantages and disadvantages, and both serving the purpose. The majority of students who rated the tutorials low and notes high, or rated them equally, were the more successful students. The averages and the comments basically signify that tutorials can be an effective tool for teaching. Pre- and Post-Tests Evaluation of the two assessments, concept map and free-response, used as pre - and post-test will be analyzed together to avoid redundancy and to allow for comparisons of questions that addressed the same concept but were presented in a different format. In the analysis of these tests, when questions of the same idea are being discussed, and there are two relevant percentages, both will be given, free response followed by concept map percentage. 28 Table 2 l0-Question free-response pre- and post-test Question #, answer Pre-Test (% correct) Post-Test (% correct) 1. green reflected 2 81 2. chlorophyll/pigments 30 87 3. energy storage 39 94 4. plants make food 34 72 5a.C02 16 62 5b.sun 52 77 5c.water 39 60 6a.glucose 25 32 6b.02 18 6O 7. breakdown of glucose to release energy 2 57 8a.glucose 0 36 8b.02 9 34 9a.CO2 9 4O 9b.ATP O 43 9c.water 0 15 10. requires 02, does not require 02 0 96 Table 3 Concept map pre- and post-test Box #, Concept answer Pre-Test (% correct) Post-Test (% correct) 11,12. Photosynthesis, Respiration 37 93 13. autotrophs, plants 65 88 14a. animals, heterotrophs 24 25, 23 14b. animals & plants 12 30 15.plants make food 43 85 16a. C02 3 1 75 16b. H20 43 68 16c. surflht 55 80 17a. glucose 29 35 17b. 02 29 70 18. glucose breakdown to release energy 2 68 19a. 02 33 63 19b. glucose 0 38 20a. C02 33 63 20b. H20 4 25 20c. ATP 10 50 29 Question 1: Why do you see green when you look at the leaf of a tree? This concept was not a part of these students’ prior knowledge. Although many of them understood the idea that it had to do with the rays of sunlight hitting them, indicated by responses such as, “it has a chemical reaction with sunlight that makes it green”, 98% of them did not know the green light was reflected, while the other colors were absorbed. However, when presenting this material in class, many students did seem to recall the fact that light was reflected, when it was presented in another way, such as asking why wearing a black shirt in the sun made a person hot while a white shirt felt cooler. They had not transferred that idea to the plant’s leaf color. This unit was obviously effective in teaching this concept since the post-test indicated 81% of the students answered it correctly. The Chromatography Lab may have had a part in helping students understand this concept, since they used the green leaf and separated out the other colors within the leaf that did not show. Question 2: What substances do plants contain that allow them to show color? 30% of students knew that chlorophyll, or a pigment, was present in the plant, which made the leaves green. In an earlier chapter, students had learned that plant cells contain chloroplasts, consisting of chlorophyll. Many of them remembered that the chlorophyll made the plant green, but there was some confusion about why it made it green. 0f the 30% of students who answered either chlorophyll or pigment, were students who indicated they understood that the pigment absorbed the sunlight and reflected the green color. Some of them may have just remembered that chlorophyll made the plant green but weren’t sure why. Many of the 70% who answered incorrectly, had the idea that it was something about the chloroplasts, but couldn’t explain it. There were responses, 30 such as, “the chloroplasts (or chlorophylls) are green, making the plant green.” Eighty- seven percent of the students then illustrated their correct understanding of this idea on the post-test. Question 3: What is the function of ATP? The idea of an energy-storage molecule called ATP was presented to the students many times prior to this unit. A 39% correct response on this item was not too surprising, especially considering that many of the incorrect responses were close to the right idea. They remembered learning it, and many knew it had to do with energy but were unsure of its exact function. By the end of this unit, only 6% of the students were still ignorant of its function. Question 4 & 15: What is photosynthesis? This question was posed in two ways to the students. Question 4 was a direct free- response, while question 15 was represented on the concept map, requiring the student to understand that the box required a definition of photosynthesis. Thirty-four percent of the students determined the appropriate response on the free-response question. However, 43% were able to identify it on the concept map. Some of the 66 (57)% who did not answer either question correctly, responded with an answer that showed they knew it was a process in which plants engaged in, but not what the purpose of that process was. Others even wrote the requirements for the process, but did not indicate what the end product of the process was, which the rubric [Appendix C-2 and C-4] required. Students needed to understand that it was food, an organic compound, carbohydrate, etc. that was produced by this process. 31 Question 5a,b,c & l6a,b,c: What substances are needed (required) by photosynthesis for it to occur? Again, this question was asked on both assessments in similar ways. With the concept map’s guidance, students were able to make sure they included all three substances. The free response question gave no corresponding indication, and students often answered with less than three. Therefore, these answers were considered separately so as to analyze what substances students understood plants required. Since there were 15 percent more students who answered C02 on the concept map than on the free response, it can be reasoned that having the knowledge that there were three items guided the students to think beyond what might have come first to mind. This is also shown by the fact that the other two responses, water and sunlight, had very similar percentages between the two assessments. Students who could answer it on one assessment, did so on both, and the percent increase of correct responses for sunlight and water were very similar. Students have familiarity with plants and they are usually aware that plants need the sunlight to grow, a concept that is instilled at a young age. Also, they have much experience with the plant’s need for water, since they may have plants at home that get watered. Many of the students who did not give sunlight and water responses were likely aware that plants use these items but did not associate them with the process of photosynthesis. However, the need for CO2, With which many students are not familiar, since it cannot be seen, felt, or smelled, is not well known. Students with no chemistry background tend to have little knowledge of gases; they see the atmosphere as “air” that they breathe, with no understanding of the various gases that “air” is composed. This would explain why only 16% of the pre-test free response answers included C02, and 32 after learning the material, this percentage jumped up 46 % on the post-test. Interestingly, an increase of 44% occurred on the concept map for the same answer. It is possible that the 15% of students who were confused by the free response question on the pre-test, were still unsure of it on the post-test, and the 46% who showed new learning on the post-test were able to answer it correctly in both areas. Question 6a,b & l7a,b: What substances are produced (end products) by photosynthesis? This concept was solicited on both assessments and there was no noticeable difference between the percentage of correct responses on pre- or post-tests. The percentages were similar for the two assessments, both before and after learning the material. However, the learning that occurred between pre- and post-tests for the concept of sugar and oxygen as products of photosynthesis was noticeable. The percentages on the pre-tests for both answers were within 11 % of each other, (the data is split as to whether those answers were from students who knew both answers or each knew one answer.) The interesting thing is that a correct response of sugar only increased by 6-7% on the post- test. A correct response of oxygen increased by 41-42% on the post-test. Question 7 & 18: What is (cellular) respiration? This question was consistent on both pre-test assessments, 2% of students knew that respiration breaks glucose down to release stored energy. Also, 53% of students answered, in some fashion, that respiration was breathing. To a person uneducated in this topic, respiration is simply an exchange of gases that occurs in the lungs. People recognize that oxygen is needed to survive, but don’t know why. They know that CO2 is exhaled, but they don’t know where it comes from or why it is released. It is satisfying to 33 see that, although the post-test did not show 100% accuracy on this question, the increase in correct responses was 55-66%. I cannot identify why there was an 11% difference between the free response question and the concept map. There does not seem to be any differing guidance in the concept map’s format to lead them to the correct answer compared to the free response question. The only potential guide could have been the subsequent boxes that asked for requirements and products. If they had continued on in the map and thought about those items, perhaps the function of respiration came to them. However, the free response question was also followed by questions regarding the requirements and products of the process, so it wouldn’t seem that those questions were helpful in that way. Question 8a,b & l9a,b: What substances (requirements) are needed by respiration in order for it to occur? There was not a single student who, on the pre-tests, could answer that glucose was a requirement for respiration. This is expected since only 2% knew that glucose had anything to do with respiration. However, the percent of students who learned that glucose was a requirement for respiration only increased by 36-38%. There was a 24% difference between the numbers of students who answered oxygen as a respiration requirement on the concept map versus the free response. The notion that the concept map provided guidance is part of the reason, however, considering that 53 percent of students thought that respiration was breathing, one would think that a higher percentage of students would recognize that oxygen was needed to breathe. In any case, the quantity of students who showed learning on this question was 25-30%. 34 Question 9a, b & 20a, b: What are the products of respiration? A prominent difference existed between pre-test concept map and free response answers. The concept map may have been problematic since it had only two boxes for products. Technically, there are three products when energy in the form of ATP is included. So, despite the omission of a third box, students may have put any combination of the three answers. Overall, students had little prior knowledge about the products of respiration. The most well known answer was C02, with 9-33% correct. This wasn’t surprising considering that many students realize that CO2 is given off during breathing. It was also expected that most students would be unable to give water or ATP as answers to this question, since they had no knowledge of respiration’s function. The largest increase in correct answers on the post-test was for ATP, at 40-43%, which is reasonable considering it’s discussed as the main purpose of the process. Correct responses of “C02” and “water” increased 30—3 1% and 21-15% respectively. The correct answer of water was low because with the knowledge that CO2 and ATP are products, and being asked for only two answers, the water answer was omitted. Question 10: Explain what the words aerobic and anaerobic mean. Definite learning occurred on this topic, illustrated by a 96% increase on the free response post-test. Students had no prior knowledge about the meaning of aerobic and anaerobic, although many responses included some idea about having to do with exercise. Students had no trouble with this question after learning it. Question 11, 12: Energy is harvested by what process, and stored by what process? This query was only present in this manner on the concept map. The free response asked for the definition of photosynthesis and respiration, but that is a more direct way of 35 soliciting the information. For this question, students needed to determine what “harvesting energy” and “storing energy” meant and then decide what processes would accomplish those goals. A little help was given on the pre-test to assist students on getting started, since frustration was rampant when they began. Students said they had no idea how to even start, and were not going to do the assignment. I hinted to them to look at the top of the sheet and figure out what the topic of the chapter was, since concept maps usually begin with the chapter’s main idea. Once they knew the two choices, they only had to figure out which was “harvesting” or “storing” energy. Even with that help, only 37% answered correctly, some still not putting in any answer, and the rest mixing up the two responses. 56% of the students learned the difference for the post-test and the 7% who still got it wrong continued to confuse the words. Question 13: What organisms conduct photosynthesis? First of all, this question, which was on the concept map, was dependent on a correct response on question 12a. Overall, 65% of students were able to respond either autotrophs or plants for this answer on the pre-test. A 23% increase occurred on the post- test. 9 Question 14a, b: What organisms conduct respiration? For the pre-test, there were some of the same problems as on question 13: students had to get 12b right and understand what the question required. There are two answers discussed here: animals or heterotrophs (considered the same here), and both plants and animals (autotrophs, heterotrophs.) It was expected that, at the outset, students would not understand that plants respire, explaining 12% correct for this question. Only 24% of students answered at least animals. Considering that 53% thought respiration was 36 breathing, one would think that they would know that at least animals respire. On the post-test, correct answers barely increased. There was an 18% increase in the correct response on the post-test. This number should have been higher after all the discussions about plants respiring and using the food they produce to make energy. Not even the response of animals/heterotrophs increased (which was considered a wrong answer.) Final Exam The final exam included 120 questions over 7 chapters. 29 questions related to photosynthesis and respiration. Tables 4 and 5 provide data for the multiple-choice section and completion section of the exam, respectively, including a brief idea of the topic and the percent of correct answers for each question. To best evaluate these results, the questions are ranked from highest percentage to lowest. This enables the well- understood topics to be compared with those that caused students trouble. 37 Table 4 Final exam multiple-choice photosynthesis & respiration questions Question Topic % Correct 6. Photosynthesis definition: take energy, make organic molecules 95 9. Energy flow through food chain 88 1. Reflection of green light 84 16. Consequence of electrons boosting to higher energy level 81 3. Atmospheric by-product of photosynthesis 77 15. Fermentation being anaerobic 74 13. Source of energy for Calvin cycle 74 5. Dark reactions of photosynthesis 70 2. Respiration definition 65 20. Photosynthesis definition, light energy conversion to chemical 63 4. Efficient ATP production due to oxygen 63 19. Recognition of respiration equation, identification of location 63 12. Source of energy for heterotrophs 63 14. Energy release through food breakdown 58 11. Krebs cycle 58 17. Calvin Cycle 53 7. ATP production quantity dependence on oxygen 51 18. Identification of water as end product of electron transport chain 37 10. Final electron acceptor in respiration 33 8. Stages of respiration 28 38 Table 5 Final exam short-answer photosynthesis & respiration questions Question Topic % correct 21. Release of energy by removal of phosphate from ATP 95 25. Source of energy for autotrophs 86 22. Formation of ADP 86 29. Function of energy lost by electrons in electron transport chain 86 26. End products of fermentation 63 28. Identification of Glycolysis by function 53 23. Identification of water formed by hydrogen, electrons, & oxygen 44 in electron transport chain 24. Identification of respiration forming ATP 37 27. Electron carriers to electron transport chain in respiration 26 The data indicates that students seemed to grasp the main ideas of the topics, generally having more difficulty with respiration. When questions were about overall processes, requiring an understanding of the “big picture”, they performed better. The percentages were lower with more specific questions, relating to intricate details and vocabulary. This was true with both concepts but photosynthesis topics seemed to be better understood than respiration topics. It seems that students have the best understanding of the general idea of photosynthesis and their comprehension weakened as the topics became more specific. However, their knowledge weakened further when the query regarded even the general idea of respiration. The lowest percentages were detailed 39 inquiries about respiration. Students apparently have trouble understanding or remembering those explicit facts. Survey Table 6 Student survey results Helped understand Helped more than Material other ways used Learning Tool 4-5 * 3 * 1-2 * 4-5 * 3 * 1-2 * Calorimeter Lab 49 27 24 ~20 45 33 Chromatography Lab 43 27 31 29 20 51 Photosynthesis Lab 45 27 29 31 29 41 Photosynthesis/Respiration Lab 45 29 29 22 33 45 Metabolizing Food Lab 49 29 22 31 37 33 Computer Tutorials 69 22 8 45 33 22 Board/Overhead Notes 63 22 14 43 39 18 * Ratings are given in percentages The student surveys showed that the laboratory experiments as a whole were rated high (4-5) 46% in helping understand the material. Labs were rated average (3) 28% and low (1-2) 27%. This data indicates that half of the students felt that the labs, in general, were valuable to their understanding of the material. The other two tools used, tutorials and notes, were previously discussed. One can see that the overall comparison of the two tools is that they were rated very similar to one another. 40 Discussion Several assignments were not finished or handed in by a few students. In the first semester of freshman year, students learn that at the high school, they have to study, do homework, and turn assignments in on time. In the middle school, they were not held accountable for getting assignments finished on time, and had little need to study. After several months of high school, freshmen begin to improve in their homework and study skills. After the first 9 weeks, grades generally improve. This research was conducted in the first semester with freshmen; therefore some of the problems, such as lab analysis questions left blank and meager attempts to understand material, resulted from the poor work habits of some students. One of the reasons that students had trouble correctly answering many of the pre- and post-test questions was their unwillingness to think. They were accustomed to memorizing facts, numbers, words, etc. but did not think about the information. They wanted to throw out answers in class, without putting thought into it, because it was easier and faster. They often used this same strategy in testing situations. On several of the pre- and post-test questions, if students had put thought into their answers, they would have performed better. They were able to answer a question requiring a general definition using only recall knowledge, but when asked a question needing similar information and more thought, they could not answer. For example, a large percentage of students could answer the question, “What is photosynthesis?” Their answers included the idea that photosynthesis is the process where plants make food or sugar. However, when later asked the question, “What are the products of photosynthesis?” students did 41 not answer “food” or “sugar”. They did not think the question through in order to link the idea of what photosynthesis did with what it produced. A reason they may have answered questions like this incorrectly was that they didn’t know what a product or a requirement was. The students learned this many times, but they may have forgotten or become confused. A third reason students had trouble with questions like this was that they were confusing the intermediate steps of the processes with the big picture. When learning photosynthesis and respiration, which each involve many steps, students are taught the reactants that go into each step as well as the products that come out of each step. For example, one of the questions asked to students many times throughout this unit was “What are the products of the light reactions needed by the dark reactions?” Of course, the response to this was ATP and NADPH. 0n the post-test, many students answered the question of photosynthesis’ end products as ATP. and NADPH. They were remembering that those were products of photosynthesis, but were confused by the difference between the overall process of photosynthesis and the intermediate steps within it. In researching this unit for use in my class, I spent five weeks preparing it at Michigan State University in the Division of Math and Sciences. I designed and/or adapted the 5 labs for use in my class. I practiced with the lab techniques and found the most effective methods for use with high school freshmen. One of the labs used in this unit, the Calorimeter Lab, was a laboratory experiment adapted from Vernier Software’s computer laboratory interface program. This lab was rated one of the lowest as compared to other labs. The computer, interface, and probes were not actually used for the Calorimeter Lab because I found there to be no 42 advantages to using the computer over standard lab equipment. However, the lab data sheets used for this lab closely approximated those produced by Vernier. The only difference between the computer lab and the standard lab was the use of the probes, instead of a thermometer, to measure the temperature of the water. I explained the changes in procedure to the students, and used the computer lab sheets to do the standard lab. I had not anticipated the difficulty the students would have with the analysis questions, which are targeted for a higher-level class. When evaluating and conducting the lab myself prior to doing it with the students, I answered the questions and found them to be adequate. However, when conducting the lab with the students, discussing the answers with them, and evaluating their responses to the questions, I realized they were inappropriate for their level. Freshmen students answer questions minimally. Also, they don’t even realize there is more to a question than just a yes, no, or simple answer. They tend to do a poor job of explaining their answers, unless they are given specific directions as to what to explain. This is why I usually use constructed-response questions. A second problem that occurred with the Calorimeter Lab is the mathematics. Prior to using this lab with my students, I followed the directions and did the calculations. 1 did not see that there would be any trouble with the math and when presenting the lab to the students, I did not discuss the math part of the lab thoroughly. While engaged in the experiment, I discovered students were having trouble with the math, due to their insufficient math knowledge and their unwillingness to figure out the problem. Once I explained the calculations to the students step-by-step, many had no trouble doing them. Overall, the laboratory experiments proved effective in helping students understand the material. There were a larger percentage of students who felt that the labs were helpful to 43 their understanding than who didn’t. Also, even when students were confused about a lab or its results, experimentation provided them with science experiences that were useful in many ways, such as following directions, making observations, recording data, measuring, formulating hypotheses, analyzing information and writing responses consistent with results. Also, just doing activities involving the specific vocabulary, concepts, equipment and data for a topic are valuable in enriching understanding. For example, in the Photosynthesis Lab, not only do students see the results of the lab, reduction of DCPIP, but they also see the chloroplast suspensions, varying photosynthetic rates, and work with light wavelengths. These are experiences that enable them to construct knowledge about the relevant concepts. Just reading the words and learning their meanings are not as beneficial as having direct experiences with them. I believe that had the post-tests been given in another way, their results could have been more valuable. Pre-tests were given as assignments that students knew they would need to do well on to get a good grade, so they would have done their best. However, post-tests were given as extra credit after the test. Students finished the 50- question unit test and were told to complete the concept map and free response. Students were appalled to hear that they needed to complete two additional tests after having just finished a difficult unit test. They were instructed that it was appreciated if they complete the tests to the best of their ability and would receive extra credit for their efforts. There is no way to know if they did the post-tests to the best of their ability. It is possible students did not try their hardest, as seen by the fact that there were students who did not complete the post-tests at all. Perhaps the post-tests should have been a part of the unit test itself for better results. 44 The exam data indicated that students retained more information on photosynthesis than respiration. There were some reasons that may explain why this occurred. First of all, more time was spent on photosynthesis. A small break occurred in the middle of this unit while we were learning photosynthesis, forcing me to spend more time on it when we returned to review before moving on. A quiz was given on photosynthesis, which permitted my students and I to ascertain where they were in their learning. By the time we got to respiration, we rushed to finish. No quizzes were given on respiration. Also, students were unenthusiastic about the material after so much time had been spent on this unit. The exam data also showed that among the topics of photosynthesis and respiration, those learned, or retained, best were the general ideas. Students seemed to know the “big picture” of the processes best, having more trouble with the specific details and vocabulary. Traditionally in science education, with a majority of students, it is the main ideas that they retain. The little details are lost in the store of knowledge students try to cram in their heads, only recalled with phrases like, “I know I learned that, but I don’t remember what it is.” In any case, it is the main ideas that we really want them to take away. Specific information about intricate processes can be releamed when needed. So, although the exam data shows that all students did not retain all of the material, it does show that they overall retained the main ideas. Also, the exam data is an average of all student scores. What the average doesn’t show is that many students received very high scores on the photosynthesis and respiration questions on the exam. On the other hand, some students were not motivated to learn or do well in the class, and did poorly on the unit test and the exam. There is 45 nothing that can be done about students who refuse to try; they will not be successful regardless of the learning tools used. The survey data showed evidence that learning styles vary among students and can make a difference in their learning. This was shown, for example, by the fact that even though tutorials received higher ratings, the ratings for notes were only slightly less. Students learned from the notes, but some felt they learned better from the tutorials. Some students learn better by listening to a teacher explain the information and paraphrasing it in their own way as they understand it. Other students benefit from having a visual method of learning, with less writing so they can focus on the visuals and the information being given. Some student comments indicated that they did not like to do labs, and would rather just do worksheets because they learned better from them. Others disliked doing worksheets, responding that they just filled in answers and didn’t learn anything from them. They added that labs helped them to understand by “seeing” the results or using the vocabulary in carrying out the procedure and answering the analysis questions. Learning styles play a big part in how a class should be taught, and many different styles should be employed. Some students will be successful regardless of what method is used because they will either find a way to learn the material or they can learn from any style. Others will struggle no matter how the information is presented and have to work hard to achieve. Many students are in the middle and using the learning style that benefits them most will help them be successful. I feel that by varying the styles of teaching that I use in my class, I can best help those middle students. For example, in one lesson, I could employ visual learning by using computer animations, auditory learning by explaining the information, tactile learning by having students 46 perform an activity that requires the use of their hands, and kinesthetic learning by having students walk around the class to accomplish parts of the activity. This unit was implemented the first semester of the year. Also, I taught another group of biology classes in the second semester, which was not the college preparatory course; therefore I did not execute my research a second time, but I was able to make changes in my teaching methods. I used what I had learned from my research and modified this course. One thing that I learned from this research and was able to modify in the second course was how to use the computer effectively. I began the research unit intending to largely replace written notes with the computer tutorials. Very few written notes were used in this unit; tutorials were the way most of the information was presented. While teaching the unit, I discovered that a higher degree of teacher involvement was necessary. So, I adjusted my plan to meet this need. I began pausing the computer to provide explanations of content that the tutorial left unclear. I rewound the animations, pausing throughout to discuss the process step by step. After finishing the unit and evaluating data and surveys, I discovered it would be beneficial to decrease my tutorial use even more. When teaching the unit the second semester, I used the tutorials and guided worksheets again, but supplemented it more with other techniques. One of the methods I used that was most effective was a magnetic model. I created large models of all the parts of a chloroplast, each having magnets on the back, and they stuck to my whiteboard. While teaching the process, I was able to “split” a water molecule into its three components, as occurs in photolysis, and move them to where they should go in the chloroplast. Students were able to watch me move the electron through the transport 47 chain and make ATP, and NADPH. I even called on students to come to the whiteboard and model the process while explaining it to the class. This method was a great tool and throughout the entire chapter, the models could be pulled out quickly and used to discuss the steps. I also made similar models for respiration so we could represent that process as well. Sometimes, the computer tutorial and my models were used in concert with each other to review a step. Without the data from this research, it would have been more difficult to ascertain the effectiveness of the tutorials, and I might not have realized that I could use them more effectively in a different way. 48 Appendix A-l Photosynthesis Lab The process of photosynthesis involves the use of light energy to convert carbon dioxide and water into sugar, oxygen, and other organic compounds. This process is often summarized by the following reaction: 6H2O + 6CO2 + light energy --> C6H1206 + 602 This process is an extremely complex one, occurring in two stages. The first stage, called the light reactions of photosynthesis, requires light energy. The products of the light reactions are then used to produce sugar from carbon dioxide and water. Because the reactions in the second stage do not require the direct use of light energy, they are called the dark reactions of photosynthesis. In the light reactions, electrons derived from water are "excited" (raised to higher energy levels) in several steps, called photosystems I and H. In both steps, chlorophyll absorbs light energy that is used to excite the electrons. Normally, these electrons are passed to a cytochrome containing an electron transport chain. In the first photosystem, these electrons are used to generate ATP. In the second photosystem, excited electrons are used to produce the reduced coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). Both ATP and NADPH are then used in the dark reactions to produce glucose. In this experiment, a blue dye (DPIP) will be used to replace NADPH in the light reactions. When the dye is oxidized, it is blue. When reduced, however, it turns colorless. 49 Since DPIP replaces NADPH in the light reactions, it will turn from blue to colorless when reduced during photosynthesis. OBJECTIVES - Use a colorimeter to measure color changes due to photosynthesis - Study the effect of light on photosynthesis. 0 Study the effect that the boiling of plant cells has on photosynthesis 0 Compare the rates of photosynthesis for plants in different light conditions. MATERIALS Colorimeter DPIP two chloroplast suspensions (in the dark) 3 cuvettes with lids large beaker or flask filled with water 0.1 M Phosphate buffer ice 5-mL pipette test tube rack 100-watt floodlight two 1-mL pipettes aluminum foil PROCEDURE 1.0btain a sample of boiled and another of unboiled chloroplasts. Keep both samples on ice at all times. 2. Connect the Colorimeter to Port 1 of the Serial Box Interface or ULI. Follow these steps to calibrate the colorimeter: 0 Prepare a blank by filling a cuvette 3% full of tap water 0 Choose Calibrate from the experiment menu and then click Perform Now 50 0 Place the blank cuvette in the cuvette slot of the colorimeter and close the lid. 0 Turn the wavelength knob of the colorimeter to the 0% T position. In this position, the light source is turned off, so no light is received by the photocell. 0 Enter “0” in the % edit box. When the voltage reading for Input 1 stabilizes, click Keep. 0 Turn the wavelength knob of the colorimeter to the Red LED position (635 nm). In this position, the colorimeter is calibrated to show 100% of the red light being transmitted through the blank cuvette. - Enter “100” in the % edit box. When the voltage reading for Input 1 stabilizes, click Keep. 0 Click OK and leave the LED on the Red setting. 3. Obtain a large beaker or flask filled with water. This will act as a heat shield for the chloroplasts, protecting them from warming due to the flood lamp. 4. Place a flood lamp on one side of the heat shield with the cuvette rack on the other. 5. Obtain a sample of boiled and another of unboiled chloroplasts. Keep both samples on ice at all times. 6. Obtain three cuvettes with lids. Label one cuvette lid with a U (unboiled), one with a D (dark), and one with a B (boiled). Cover the outside of cuvette D with aluminum foil to prevent light from getting into the cuvette. The lid is opaque, so you do not need to cover it. 7. Gently suspend the chloroplasts in the unboiled and boiled chloroplast suspensions. 51 8. Add 2.5 mL of DPIP solution to each of the cuvettes. Perform the following steps as quickly as possible and proceed to step 5. *Cuvette U: Add 3 drops of unboiled chloroplasts. Place the lid on the cuvette and gently mix; try not to introduce bubbles in the solution. Place the cuvette in the light. * Cuvette D: Add 3 drops unboiled chloroplasts. Place the lid on the cuvette and gently mix; try not to introduce bubbles in the solution. Place the f oil-covered cuvette in the light. Make sure no light can penetrate the cuvette. * Cuvette B: Add 3 drops boiled chloroplasts. Place the lid on the cuvette and gently mix; try not to introduce bubbles in the solution. Place the cuvette in the light. 9. At time = 0, put each of the cuvettes into the colorimeter in the slot and close the lid. Allow 10 seconds for the readings to stabilize, and then record the absorbance value displayed in the meter window in Table 1. Remove each cuvette and place in its original place in front of the light. 10. Repeat step 5 at 5 minutes, 10 minutes, 15 minutes, and 20 minutes. 11. Data is entered into the table and a rate of photosynthesis for each of the chloroplast suspensions is determined. 12. Look at the following data table to answer the questions below regarding this experiment. 52 Data Table 1 Time Absorbance Absorbance Absorbance (min) unboiled In dark Unboiled 0 5 10 15 20 Analysis Questions 1. Is there evidence that chloroplasts were able to reduce DPIP in this experiment? Explain. 2. Were chloroplasts able to reduce DPIP when kept in the dark? Explain. 3. Were boiled chloroplasts able to reduce DPIP? Explain. 4. What conclusions can you make about the photosynthetic activity of spinach? 53 Appendix A-2 Name Biology Photosynthesis & Respiration Lab 1. Do plants do photosynthesis, respiration, or both? Explain. 2. Fill in the blanks of the following sentence: The process of photosynthesis involves the use of energy to convert and into 3. Write the chemical equation for photosynthesis: 4. Fill in the blanks of the following sentences: Cellular respiration refers to the process of converting the chemical energy of into can be oxidized (all hydrogen and oxygen removed) completely if is present. 5. Write the chemical equation for respiration: 6. All organisms, including animals and . oxidize glucose for energy. This energy is used to convert ADP and into 7. If a plant is photosynthesizing, explain what the levels of O2 and CO2 should be doing while it occurs. 02 CO2 54 8. If a plant is respiring, explain what the levels of O2 and CO2 should be doing while it occurs. 02 C02 9. If plants were placed in the dark, what would you expect the levels of O2 and CO2 to be doing? Explain. 02 CO2 Data Table 1 Leaves C02 rate of 02 rate of production/consumption production/consumption (ppm/min) (ppm/min) In the dark In the light 1.Were either of the rate values for CO2 a positive number? If so, explain why and what this tells us. 2.Were either of the rate values for 02 a negative number? If so, explain why and what this tells us? 55 3. Do you have evidence that cellular respiration occurred in leaves? Explain. 4. Do you have evidence that photosynthesis occurred in leaves? Explain. 5. List three factors that might influence the rate of oxygen production or consumption in leaves? Explain how you think each will affect the rate? 56 Appendix A-3 Calorimeter Lab Food supplies energy for all animals - without it we could not live. The quantity of energy stored in food is of great interest to humans. The energy your body needs for running, talking, and thinking comes from the foods you eat. Not all foods contain the same amount of energy, nor are all foods equally nutritious for you. An average person should consume a minimum of 2,000 kilocalories per day. That is equivalent to 8,360 kilojoules. In other words, 1 kilocalorie is equal to 4.18 kilojoules. Calories and joules are both units of energy. We will use both calories and joules because calories are the units used in the information about the food we eat. Joules are the accepted SI metric standard. You can determine energy content of food by burning a portion of it and capturing the heat released to a known amount of water. This technique is called calorimetry. The energy content of the food is the amount of heat produced by the combustion of 1 gram of a substance. It is measured in kilojoules per gram (kJ/g) OBJECTIVES In this experiment, you will * monitor the energy given off by food as it burns. *determine and compare the energy content of different foods. 57 MATERIALS food holder (cork w/ bent paper clip stuck out of the top) food samples (cashew, frito, etc) aluminum foil pop can thermometer 2 stirring rods ring stand & ring PROCEDURE 1. Obtain and wear goggles. 2. Obtain materials. Mount the food in or on the food holder. Wrap the aluminum foil so that the top portion of it wraps around the bottom of the pop can. The bottom of the foil should come forward making an opening where a match could be inserted to light the food. See Figure l for an illustration of the food insulator. 3. Set up the apparatus as shown in Figure 1. . Record the total mass of the food holder, insulator, and food sample in Table 1. . Obtain the mass of the dry pop can and record. . Measure 50 mL of water with a graduated cylinder and pour into the pop can. . Mass the pop can with water and record 58 . Insert a glass stirring rod into the holes in the pop can and suspend it from the ring. 4. Put a thermometer into the pop can and measure the temperature of the water. (The water should be room temperature or below.) Record the temperature in the table. 5. Place the food holder/insulator setup under the can and arrange it so that the pop can will fit into the opening of the foil and close the space between the food and can. 6. Light the food with a match held through the opening under the food. Do not hold the match under too long or it will affect the data and ruin the experiment. Light the food quickly. 7. If the temperature of the water exceeds 60° C, blow the flames out. Record the maximum temperature of the water in table 1. 8. After 4-minute flames, if the food is still burning, blow the flame out. Record the maximum temperature of the water in table 1. 9.Determine the final mass of the food sample, holder, and insulator and record in table]. 10. Place burned food, matches, wooden splints in the container supplied by your instructor. 11. Repeat steps 3-9 for a second food sample. 59 DATA Table 1 Measurements Sample 1 . Sample 2 . Food Used Mass of empty can (g) Mass of can plus water (g) Minimum temp. of water Maximum temp. of water Initial mass of food (g) Final mass of food (g) Table 2 Calculations Sample 1. Sample 2 . Mass of water (g) Temp. Change of water (degrees C.) Mass of food change (g) Energy gained by water (J) Energy content of food (J/g) 60 PROCESSING THE DATA Record the following calculations in Table 2. 1. Calculate the change in mass of each food sample. Show your calculations. 2. Calculate the changes in the temperature of the water, temp change. Record this in Table 2. Show your calculations. 3. Calculate the energy gained by the heated water. Show your calculations. To do this, use the following equation: Energy gained by water = (mass of water) x (Dt of water) x (4.18 J/g C) 4. Convert the energy you calculated in step 3 to kilojoules ( lkJ = 1000 J) 5. Convert the kilojoules to kilocalories (l kC = 4.18 kJ) Analysis Questions 1. Which of the foods has the greatest energy content? 2. Which of the tested foods is the best energy source? Why? 3. What was the original energy source of the foods you tested? 4. Why might some foods with lower energy content be better energy sources than other foods with higher energy content? 5. Would you expect the energy content values that you measured to be close to the value listed in dietary books? Why? 61 Appendix A-4 Chromatography Lab Purpose: You are a plant physiologist working for a natural clothing company. All the garments manufactured by your company are made from natural plant fibers and colored with natural dyes. Your company wants you to come up with a new yellow dye for their new line. You know of a plant that you believe contains the particular pigment you are looking for. You need to separate the pigments in an extract from the leaves of this plant to determine whether the leaves contain the yellow pigment. The separation technique you decide to use is paper chromatography. Background: The leaves of most plants contain many different pigments, or light-absorbing compounds. Chlorophyll, the main pigment of green plants, is needed for photosynthesis. The primary purpose of chlorophyll is to capture light energy, which is converted to chemical energy during photosynthesis. Chlorophyll is the most abundant and important photosynthetic plant pigment and exists in several forms, including chlorophyll a and chlorophyll b. Both chlorophylls absorb blue and red light and reflect green light. Chlorophyll often hides the other pigments present in leaves. In autumn, chlorophyll breaks down, allowing xanthophyll, which reflects yellow light, and carotene, which reflects orange light, to show their colors. Other pigments may also be present in leaves. The individual pigments in a mixture of pigments from a leaf may be separated by the technique of paper chromatography. Chromatography means color writing. The 62 separation takes place by absorption and capillarity. The paper holds substances by absorption. Capillarity pulls the substances up the paper at different rates. Pigments are separated on the paper and show up as colored streaks. The pattern of separated components on the paper is called a chromatogram. The relative rate of migration, the Rf value, for each pigment can be determined from the chromatogram. The Rf value is the ratio of the distance a pigment moved on the chromatogram to the distance the solvent front moved. Materials: chromatography paper nail or other hard, flat object Chromatography solvent (1 ETOH; 2Acetone; 1D. H20) spinach leaves jar petri dish lid tape pencil Procedure: 1. Obtain materials and cut one end of the paper into a point by cutting the edges off each side. (See Figure 1) 2. Draw a pencil line across the bottom of the strip. 3. Take the spinach leaf and, using the nail, grind the leaf onto the pencil line so that the green color remains on the paper. (Be careful not to put a hole in the paper.) 63 4. Pour chromatography solvent into the jar so that there is about 5 mm in the bottom. 5. Put the paper into the jar so that the point is half in the solvent and secure the top of the paper with tape to the side of the jar so that it doesn't move and doesn't touch the side of the jar. 6. Watch the solvent rise up the paper, carrying and separating the pigments as it goes. After five to seven minutes, you will notice an obvious change in the paper within the jar. At the instant the solvent reaches the top of the chamber, remove the paper, and let it air dry. 7. Observe the bands of pigment. Identify the pigments by their colors: carotene (orange), xanthophyll (yellow), chlorophyll a (yellow-green), and chlorophyll b (blue- green). With a pencil, mark the highest point the solvent traveled up the chromatography paper strip. Also, make a pencil mark at the center of each of the separated pigments. Write your name on the strip as well. 8. Measure the distance in mm of the solvent from its starting point to the highest point it traveled on the paper strip. Then measure the distance traveled by the different pigments from the starting point to the center of each pigment band. Record your measurements in the data table below. 64 Data: Band Number Pigment Color Migration distance in mm Rf value 1 (mp) Solvent NA NA NA 9. In the space provided at right, make a sketch of the chromatogram. The chromatogram of the simulated plant pigments will fade over time, so it is necessary to record data in order to preserve it. 10. Use the following formula to calculate the Rf values for each pigment as a decimal fraction. Record your answers in the data table above. Rf = distance substance’s pigment traveled distance solvent traveled 11. Dispose of your materials according to the directions from your teacher. 12. Clean up your work area and wash your hands before leaving the lab. 65 Analysis 13. Describe what happened to the original spot of simulated plant pigment. 14. Which of the pigments migrated the farthest? Why? Conclusions 15. Would a plant containing the pigments shown in the data table on the previous page be a source for yellow dye? Explain your answer? 16. What other colors of dye might be available from the same plant? Explain your answer. 17. Which of the chlorophyll forms is more soluble? Why? 66 Appendix A-S Metabolizing Food Lab Purpose To study three different forms of metabolism and determine which form is used by each organism. Background Metabolism is the term used to describe all of the chemical reactions that occur within an organism. Your cells get most of the energy needed for metabolism from the foods you eat. As food is digested, chemical reactions convert the chemical energy in food molecules to forms of energy that can be used by cells. When food is broken down, the metabolism can occur in several ways. The organism may use oxygen as an electron acceptor in the electron transport chain, which is aerobic respiration. The organism may use another substance, such as Nitrate or Sulfate, as an electron acceptor, which is anaerobic respiration. In both cases, the electron acceptor must be provided to the organism by an outside source. However, some organisms can metabolize their food without being provided with an electron acceptor because they synthesize their own acceptor and use it in fermentation to free the NAD+, recycling it to be used again. In all cases, respirers must be provided with the electron acceptor and produce an inorganic product. Ferrnenters produce their own electron acceptor and produce an organic product. In this lab, you will study two organisms and discover what type (s) of metabolism they use. You will attempt to grow them 1.) with oxygen, 2.) without oxygen but in the presence of an alternate electron acceptor, Nitrate, and 3.) without oxygen or 67 any other electron acceptor. Their growth or lack of growth will indicate what type (s) of metabolism they are capable of conducting. Materials (per student): 4 large sterile test tubes with caps (prepared as described in teacher notes) 1 tube containing yeast growth medium with 0.5% N03 1 tube containing yeast growth medium without N03 1 tube containing trypticase soy agar with 0.5% N03 1 tube containing trypticase soy agar without N03 yeast culture (see preparation in teacher notes) Pseudomonas aeruginosa (denitrifying bacteria) culture (commercial stock) Inoculating loop Bunsen burner Large test tube rack Procedure: Sterilize inoculating loop by putting the loop end into flame until it turns red and moving up the wire until the entire wire has been sterilized. 1. Open yeast culture container and use loop to scoop out some specimen. 2. Open sterile test tube labeled Y + and sterilize mouth of test tube by running it across the flame several times. 3. Using a back and forth motion, spread the specimen on the surface of the agar, completely covering the area. 68 4. Make sure to have some specimen on the loop and stab the inoculating loop into the middle of the agar and push it all the way to the bottom of the tube. 5. Sterilize the test tube mouth again before recapping it and replace it in the rack. 6. Sterilize the loop in the flame. 7. Repeat steps 1-7 with test tube labeled Y- and the yeast culture. 8. Repeat steps 1-7 with test tubes labeled P+, and P- and the P. aeruginosa culture. 9. When all 4 tubes have been inoculated, place the test tube rack in a safe place to be stored overnight. The specimen prefer ~30 degrees Celsius, so if room temperature is much colder than this, you may want to incubate the tubes. 10. Resterilize loop to avoid contamination, properly put away cultures to maintain sterility, and clean lab station. 11. Afier 24 hours, examine the tubes for growth and record the data in the data table below. Indicate a (+) for presence of growth and a (-) for absence of growth. Data Specimen Growth Nitrate Present (+) Nitrate Absent (-) Organism _ Surface Deep Surface Deep Yeast P. aeruginosa 69 Analysis 1. If a specimen grows on the surface of the agar (with or without the presence of nitrate), what type of metabolism does that indicate? Why? 2. If a specimen grows in the deep in the presence of Nitrate and does n_ot grow in the absence of nitrate, what type of metabolism does that indicate? Why? 3.If a specimen grows in the deep without the presence of nitrate, what type of metabolism does that indicate? Why? 4.If a specimen will not grow in the deep without the presence of nitrate, what does that indicate? Why? Conclusion 1. What type of metabolism does this strain of Pseudomonas aeruginosa exhibit? Explain. 2. What type of metabolism does yeast exhibit? Explain. 70 3. Why was yeast able to grow in the deep without nitrate present while P. aeruginosa was not? 4. Fill in the concept map below regarding the types of metabolism and an explanation of each (large box at bottom) Metabolism Electron acceptor Electron acceptor Must be provided need not be provided 1 l 71 Teacher Notes Preparation of Trypticase Soy Agar (1 L) Trypticase Soy Broth 30 g Distilled H20 up to 1 L Bacto-agar 15 g If N03 desired - Make 10% KNO3, add 50 mL KNO3 to 1 L Agar Yeast Growth agar Glucose 20 g (NH4)ZSO4 2 g yeast extract 5 g distilled water up to 1 L agar 15 g Pour 1 tube of each of the following solutions for each student group Tubes with yeast growth medium with Nitrate — label Y+ Tubes with yeast growth medium without Nitrate - label Y- Tubes with Trypticase Soy medium with Nitrate - label P+ Tubes with Trypticase Soy medium without Nitrate - label P- Be sure to use aseptic technique when pouring tubes or sterilize them after preparation to avoid contamination. Yeast culture can be made by purchasing live yeast from grocery store and adding contents of package to l L distilled water. Add 3% or 30 g sucrose, cover, and set aside for several hours. Pseudomonas aeruginosa can be purchased from a biological supply store 72 Appendix B-l Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 2-1 Overview Biostory - What do plants need in order to make food? Learn - Stage 1 - Light energy is absorbed Stage 2 - Light energy is converted to chemical energy which is stored in Water is needed to split apart, what is released as a by-product? Stage 3 - chemical energy is used to make C02 are used to build carbohydrate molecules inorganic ---> organic What is the chemical equation of photosynthesis? Photosynthesis occurs where? What makes a leaf look green? What are the disks where photosynthesis takes place? Summarize the definitions below in your own words autotroph Carbon fixation heterotroph Try It - Click on the plant cell. What type of cell is this? 73 Click the label where it shows where photosynthesis occurs. Where does it occur? On Your Own - Drag each label in the activity drawer to the diagram. What does the plant use the sugars it makes for? Review Questions 2-1 An Overview 1. What is an autotroph? 2. How are heterotrophs different from autotrophs? 3. What are the three stages of photosynthesis? 4. What does a plant cell do with the light energy it captures? 5. What chemical equation is often used to summarize the process of photosynthesis? 6. In what part of a plant cell does photosynthesis occur? 74 Appendix B-2 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 2-2 Absorbing Light Energy Biostory - Why are greenhouses used to grow plants? Why are regular light bulbs not sufficient for plants to grow as well? Learn - Photosynthesis begins with the absorption of light. *A pigment is a molecule that absorbs some colors of light and reflects others which produces the color of an object. *Chlorophyll reflects green light while other pigments reflect other colors *Where is chlorophyll? *The inside of a chloroplast is filled with green disks, these are *Stage 1 occurs in which contain *The outside of the thylakoid is called the membrane and there is a space inside the thylakoid *The membrane has clusters of chlorophyll and other pigment molecules. *As the clusters absorb light, some gain energy and get excited. *These electrons will power photosynthesis as they release their extra energy. *On a sunny day, millions of excited electrons form within a leaf each second. Try It - Use the slider to vary the light intensity. Watch what happens to the electrons both in the graphic illustration as well as the illustration of the membrane. 75 As the light intensity increases, what is happening to the electrons? On Your Own - Click the label that shows where photosynthesis occurs in the cell. Where does photosynthesis occur? Click the label that shows where chlorophyll molecules are found. Where are they found? They are scattered where in the chloroplast? Review Questions 2-2 Absorbing Light Energy 1. What role do pigments such as chlorophyll play in photosynthesis? 2. Where are the photosynthetic pigments located in a plant? 3. How is the energy in light transferred to chlorophyll? 4. What is the name given to electrons that have been raised to a higher energy state? 76 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 2-3 Electron Transport Chain Biostory - why is water important to plants? Plants cannot do what without water? Learn - Stage 1 - Light Absorption Stage 2 - Energy Conversion light energy --> chemical energy Stage 3 - inorganic --> organic *light strikes chlorophylls, electrons get excited, pass through electron transport chain, before they leave they must be replaced from *excited electrons can leave chlorophyll, enter lst ETC, give off excess energy, used to transport H ions from stroma to thylakoid space. *process repeated millions of time, build up H ions, use H ions to make *electrons reach end of lst ETC, have lost most energy, passed to 2nd cluster of chlorophylls, after getting excited again, are passed to 2nd ETC. *H ions and electrons join with NADP+ (electron acceptor), which forms NADPH *energy from excited electrons is stored in NADPH *NADPH carries the electrons and the energy to other molecules, it is an *The energy produced in stage 2 is used to make in stage 3. Try It - Identify the parts of a chloroplast that are involved in the parts of photosynthesis. Drag the labels from the activity drawer to identify the parts of a chloroplast involved in stage 2 of photosynthesis. 77 On Your Own - Drag the materials needed for stage 2 of photosynthesis from the activity drawer to the correct box in the diagram. After each one, listen to the review of the steps. Why is water needed here? NADP+ is needed to do what? Review Questions 2-3 Electron Transport Chain 1. What is an electron transport chain? 2. In plants, where are the electron transport chains for photosynthesis located? 3. How is water used during photosynthesis? 4. What happens to the concentration of hydrogen ions inside a chloroplast as electrons move through the electron transport chains? 5. Where do the excited electrons end up after they pass through the electron transport chains of photosynthesis? 78 Appendix B-4 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 24 Making ATP Biostory - Why is phosphorous needed by plants? Learn - *ATP is made during stage 2. ATP stands for Draw a diagram of ATP here Write ATP equation: Where is the energy stored in an ATP molecule? How does the energy become available to a cell? *H ions build up inside thylakoid, electrons flow through ETC in thylakoid membrane, some H ions come from water split, others are transferred in *charge produces H ions current which powers production of ATP *H ion can leave thylakoid by diffusing through channel protein *the flow supplies energy needed (from concentration gradient) to add phosphate groups to ADP molecules, forming ATP. Try It - Build an ADP molecule. Drag the necessary materials from the activity drawer to the monitor window. The energy icon will form one bond. (Drag each item needed in the correct amounts to the window, the computer will assemble the pieces.) Click next when done. Change the ADP molecule into an ADP molecule. Drag the necessary materials from the activity drawer to the monitor window. Click check it when done. 79 How many energy icons are needed in order to make the molecule? On Your Own - Think about how ATP is made during photosynthesis. Drag the pictures from the activity drawer to the four answer boxes so they are in the correct order. Then click check it. Summarize the four steps in order. 1. 2. 3. 4. Review Questions 2-4 Making ATP 1. What are the parts of an ATP molecule? 2. What is the importance of ATP to a cell? 3. Where is ATP made during photosynthesis? 4. What role do hydrogen ions play in the making of ATP during photosynthesis? 80 Appendix B-5 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 2-5 Calvin Cycle Biostory - What do plants need in order to make food? Learn - Inorganic CO2 is made into organic compounds, this takes place in the *CO2 is added to a 5-C molecule to make a 6-C molecule. *6-C molecule splits into 2 3-C molecules, this is called *3-C molecules are converted to 3-C sugar *ATP and NADPH provide energy to make 3-C sugar *A is transferred from ATP for energy *NADPH provides energy by donating and * As long as C02 is available, this will continue, some 3-C will leave cycle to make for the plant, most will remain in the cycle to regenerate the 5-C molecule needed to keep it going. Try It - Click the 2 items that start the Calvin cycle. Click Check it when done. *Fill in what start it Click the materials that supply energy to the Calvin cycle. Click Check It when done *Fill in the materials Click the molecule that provides hydrogen ions to the Calvin cycle. Click check it. *Fill in the answer Click the end product of the Calvin cycle. Click check it when done. *Fill in the product 81 How many CO2 molecules must be added to the cycle to get one 3-C sugar molecule? On Your Own - Drag items from the activity drawer to the diagram to complete the Calvin Cycle. Which of the 5 items are used more than once in the diagram? What is the overall purpose of the Calvin cycle? 1. 2. Review Questions for 2-5 Calvin Cycle 1. What happens during the Calvin Cycle? 2. What materials are needed for the Calvin cycle? 3. What materials are produced by the Calvin cycle? 4. What is the importance of the Calvin cycle? 82 Appendix B-6 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 2-6 Regulation Biostory - Greenhouses are managed to control environment. Learn - Four factors in the environment affects photosynthesis. Light intensity *affect rate of photosynthesis *increases to a point, then levels off *at this point, photosynthesis has reached maximum potential Color of Light *chlorophyll does not absorb green light -->which makes green leaves *they absorb other colors which are used by photosynthesis *the most energy absorption occurs in the regions * produces the lowest rate of photosynthesis Temperature *photosynthesis increases as temperature increases *as temp rises above a certain point - photosynthetic rate decreases *temps below freezing kill cells which *enzymes assist chemical reactions, as temp increases, reactions in enzymes *extreme temps cause enzymes to change shape which interferes with rx *on a hot, sunny day, plants struggle to maintain homeostasis *they lose water through stomata in their leaves in order to 83 * cannot enter leaf if stomata are closed Amount of CO2 * there needs to be CO2 in the air in order to have photosynthesis occur Try It - Click the buttons in the activity drawer to project light of different colors on the tomato plant. Watch what happens to the amount of sugar and oxygen produced by photosynthesis. Which colors produce the least sugar and oxygen? On Your Own - Determine the optimal conditions for plant growth. Use the control panel to change the conditions. Choose a set of conditions, and then click check it to get the results. Write high, medium or low for each of the following conditions for optimum results. CO2 - temperature - Light - Review Questions 2-6 Regulation 1. In addition to water and mineral nutrients, what are four environmental factors that affect the rate of photosynthesis? 2. Which colors of light promote the fastest rate of photosynthesis? 3. What combination of light intensity and temperature promotes the fastest rate of photosynthesis? 4. Why do very high or low temperatures slow the rate of photosynthesis? 84 Appendix B-7 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 3-2 Glycolysis Biostory - Why is it recommended to athletes that they eat starches before exercise? Learn - ATP supplies the body with energy. Review the making of ATP. *Cells make ATP during cellular respiration. * lst stage - Reactions occur in the cytosol of cell. *Glucose broken down into 2 3-C molecules of pyruvic acid. *ATP passes a P to a glucose, glucose binds, ATP passes another P to glucose, binds *6-C molecule splits in half, each 3-C molecule picks up another P, H ion passed to NAD+ (electron acceptor, electron carrier) *NAD+ stores energy --> makes NADH (carrying the energy of the H ion) *4 P groups make more ATP - 2 ADP come in and get the P groups, 2 more ADP come in and get the other P groups. How many ATP are made? How many are used? What is the net gain of ATP molecules? Try It - How many glucose molecules must go through glycolysis to result in a net gain of eight ATP molecules? Drag the correct number of glucose molecules to the " glucose in " box. Click check it when you are done and reset to try it again. On Your Own - Complete the diagram of glycolysis by dragging items from the activity drawer to the correct boxes. 85 How many NADH molecules are formed by glycolysis? Review Questions 3-2 Glycolysis 1. What is glycolysis? 2. Where does glycolysis occur? 3. What is the starting material for glycolysis? 4. What are the products of glycolysis? 5. Why is there a net gain of only two ATP molecules per glucose molecule during glycolysis? 86 Appendix B-8 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 3-3 Krebs Cycle Biostory - Why do cells need oxygen? Learn - After glycolysis, cellular respiration continues in the mitochondria as long as oxygen is present *CO2 is removed from the Pyruvic acid (PA) made in glycolysis. *remaining 2-C acetyl groups attach to Coenzyme A (CoA), making acetyl-CoA. *electron carrier is also produced. *acetyl CoA enters Krebs Cycle *acetyl passed to a 4-C molecule--->forms 6-C molecule, leaving CoA free to react with another PA *6-C molecule loses 1 CO2 , gets hit by NAD+, transfers H ions and electrons to make NADH *this occurs a 2nd time - another CO2 lost, another NADH produced. *ADP hits 4-C, grabs free P to make ATP *4-C molecule gives off 3 electrons which are used to make another NADH, FADH2 *4-C molecule recycled, ready to be used again in the cycle Try It - Click the two items that start the Krebs cycle. What are the two items? Click the four electron carrier molecules produced during the Krebs cycle. What are the four carriers? 87 Aerobic respiration requires oxygen and gives off carbon dioxide. Click on the two molecules of carbon dioxide. The Krebs cycle produces molecules that store energy in the cell. Click the molecule that is the main energy source for cell metabolism. What is it? On Your Own - Drag the items in the activity drawer to complete the diagram of the Krebs cycle. Draw a simple diagram of the Krebs cycle below. Review Questions 3-3 Krebs cycle 1. What substance must be present for the Krebs cycle to occur? 2. Where does the Krebs cycle occur in a eukaryotic cell? 3. What are the products of the Krebs cycle? 4. What are the starting materials for the Krebs cycle, and how are they produced? 88 Appendix B-9 Biology Ch 5 Photosynthesis & Respiration Interactive Tutor 3-4 Electron Transport Chain (ETC) Biostory - Why is oxygen important to body cells? Learn - mitochondrion, have inner membrane with molecules inside *when oxygen is present, electrons pass from one molecule to the next in ETC *as electrons pass through ETC, H ions build up in outer compartment *H ions help to make ATP *electron carriers, bring electrons to ETC *NADH carries H ion w/ extra electrons, the ion & electron delivered to lst cluster of molecules. ion crosses membrane, electrons move along ETC *molecule carries to 2nd cluster, more H ions move across membrane, electrons passed to last cluster *FADH2 delivers H ions and electrons , more H ions move across *H ions now built up in outer compartment *concentration of H ions in outer compartment stores energy used to make ATP. *H ions (from build up outside membrane) pass through by diffusion, as pass P is added to a ADP to make ATP *energy from flow of H ions is used to add P to ADP *when electrons get to end of ETC, accepted by oxygen molecules *each oxygen atom takes on 2 electrons and 2 Hydrogen ions to make water *electrons must leave chain so more can enter 89 *oxygen allows ETC to keep from backing up, so flow of electrons will continue and make more ATP * if no oxygen, ETC will back up, Krebs cycle backs up and only glycolysis will occur *so oxygen is called the *a cell gains only 2 ATP molecules for each glucose molecule from glycolysis *when 0 is present, NADH and FADH2 are produced, up to 3 ATP are produced from each NADH, up to 2 ATP are made from each FADH2 *up to 38 ATP molecules made per glucose under aerobic (with oxygen) conditions (2 from glycolysis, 36 from Krebs and ETC) Try It - Drag the three materials needed for the electron transport chain from the activity drawer to the correct place in the diagram. What are the materials needed for the ETC? On Your Own - Drag labels from the activity drawer to identify the steps in cellular respiration. When you finish, click check it. What are the three steps in order of aerobic respiration? Review Questions 3-4 Electron Transport Chain 1. Where are the electron transport chains of cellular respiration located? 2. What happens in the electron transport chains of cellular respiration? 3. What is the role of oxygen in the ETC? 90 Appendix C-l Photosynthesis & Respiration Pre-Test & Post-Test 1.Why do you see green when you look at the leaf of a tree? 2.What substances do plants contain that allow them to show color? 3. What is the function of ATP? 4. What is photosynthesis? 5. What substances are needed by photosynthesis in order for it to occur? 6. What substances are produced by photosynthesis? 7. What is cellular respiration? 8. What substances are needed by respiration in order for it to occur? 9. What substances are produced by respiration? 10. Explain what the words aerobic and anaerobic mean. 91 Appendix C-2 Photosynthesis & Respiration Pre-Test Rubric 1.Why do you see green when you look at the leaf of a tree? Green is reflected 2.What substances do plants contain that allow them to show color? Pigments, chlorophyll 3. What is the function of ATP? Store energy 4. What is photosynthesis? Process of plants producing carbohydrates from inorganic compounds (or plants make food) 5. What substances are needed by photosynthesis in order for it to occur? C02, H20, sunlight 6. What substances are produced by photosynthesis? 02, sugar (food) 7. What is cellular respiration? Breakdown of glucose to release stored energy 8. What substances are needed by respiration in order for it to occur? 02, glucose 9. What substances are produced by respiration? C 02, H20, ATP 10. Explain what the words aerobic and anaerobic mean. Aerobic — with oxygen, Anaerobic — without oxygen 92 Appendix 03 Concept Map Pre-Test and Post-Test Energy A is stored during / \ is harvested during 11. 12. Organisms that do this are 13. 14. which is which is 15. 18l | l l I l . which requires which requires 1 63 1 61) i 1 6c 92L 19b. and gives off as end products and gives off as end products 17a. 1 17b. 1 20a. 1 1 20b. 1 l which are then used by which are then used by l l l l 93 ll. 12. 13. 14. 15. 16. 17. 18. 19. 20. Appendix C-4 Rubric for Concept map pre-test and post-test photosynthesis respiration autotrophs heterotrophs, plants & animals plants make their own food CO2, H2O, sunlight oxygen, sugar breakdown of glucose to release energy oxygen, glucose CO2, H2O, ATP (21 . respiration 22. photosynthesis) not graded as part of the pre- and post-test 94 Appendix C-S Photosynthesis / Respiration Survey 0 Rate each of the following activities with 5 (being the best) to 1 (being the least). Activity Difficulty Enjoyability Helped Helped understand more material than other ways Calorimeter Lab Chromatography Lab Spectrophotometry Lab Photosynthesis & Respiration Lab Metabolizing Food Lab Interactive Tutorials Board / Overhead Notes 95 Appendix C-6 CP Biology Exam 2 Photosynthesis & Respiration Questions only __ l. Chlorophyll is green because a. it reflects green wavelengths of light. b. it absorbs blue and yellow wavelengths, which make green. c. of an optical illusion caused by transmitted light. (1. it absorbs green wavelengths of light. 2. The process of cellular respiration a. occurs only in animals. b. breaks down food molecules to release stored energy. c. is performed only by organisms that are incapable of photosynthesis. (1. occurs before plants are able to carry out photosynthesis. __ 3. The major atmospheric by-product of photosynthesis is a. nitrogen b. water c. carbon dioxide d.oxygen 4. Cells produce ATP most efficiently in the presence of a. water b. oxygen c. glucose (1. carbon dioxide 96 5. The dark reactions of photosynthesis a. are light-independent. b. require ATP and NADPH. c. Generate sugars. d. All of the above __ 6. The process in which plants capture energy and make organic molecules is known as a. development b. photosynthesis c. homeostasis (1. evolution 7. The total amount of ATP that a cell gains for each glucose molecule depends on the presence of a. glucose b. carbon dioxide C. water .0- oxygen __ 8. Cellular respiration takes place in two stages: a. glycolysis, then aerobic respiration. b. glycolysis and fermentation. c. electron transport chain, then fermentation. (1. None of the above. 97 a. b. C. d. a. b. C. d. 9. Energy flows from the sun through the living world when animals eat other animals that have eaten plants. animals eat plants. Plants capture sunlight and produce carbohydrates. All of the above 10. The final electron acceptor in aerobic respiration is NADPH. ATP. water. oxygen. 11. In cellular respiration, a two-carbon molecule combines with a four- carbon molecule as part of a. b. C. d. the electron transport chain carbon dioxide fixation. glycolysis. the Krebs cycle. 12. Heterotrophs get energy a. b. C. d. from organic molecules. from breaking down food molecules. through cellular respiration. All of the above. 98 13. The energy used in the Calvin cycle for the production of carbohydrate molecules comes from a. the Krebs cycle. b. ATP only. c. ATP and NADPH. d. carbon dioxide. __ 14. When living cells break down food molecules, energy is a. stored as ADP. b. stored as ATP. 0. released as heat. (1. Both (b) and (c). 15. Fermentation enables glycolysis to continue under a. photosynthetic conditions. b. aerobic conditions. c. anaerobic conditions. (1. None of the above. 16. When electrons of a chlorophyll molecule are raised to a higher energy leveL a. they enter an electron transport chain. b. they form a glucose bond. c. carotenoids are converted to chlorophyll. (1. They become a photon of light. 99 17. During photosynthesis, the series of reactions that create the complex carbohydrates needed for energy and growth is called a. the Krebs cycle. b. the electron transport chain. c. the Calvin cycle. (1. None of the above. 18. Water is an end product in a. the electron transport chain. b. lactic acid fermentation. c. alcoholic fermentation. d. the Krebs cycle. The questions below refer to the following balanced chemical equation. C6H1206 + 602 + ADP + P 9 6CO2 + 61120 + Molecule A 19. Refer to the equation above. The process summarized by the equation begins in the cytoplasm of a cell and ends in the a. cell membrane. b. mitochondria. c. cytoplasm d. endoplasmic reticulum. 100 —- ‘J h—j It! a. b. C. d. 20. Light energy is converted to chemical energy through the process of cellular respiration. glycolysis fermentation. photosynthesis. 21. When a phosphate group is removed from an ATP molecule, energy is 22. When a phosphate group is removed from an ATP molecule, a(n) molecule is formed. 23. Hydrogen ions combine with electrons and oxygen forming at the end of the electron transport chain. 24. ATP is an end product in the process of 25. Autotrophs are organisms that use energy from or inorganic substances to make organic compounds. 26. During fermentation, either ethyl alcohol and carbon dioxide or is formed. 27. Electrons that provide energy for the production of most of a cell’s ATP are carried to the electron transport chain by and molecules. 101 28. Glucose is split into smaller molecules during a biochemical pathway called 29. The energy lost by electrons while in the electron transport chain is used to pump ions into the thylakoid. 102 Appendix C-7 Rubric for CP Bio Exam 2: Photosynthesis & Respiration Questions only PWSP‘MPP‘P?‘ NNNNNHHh—th—ID—I—II—ID—‘t—ib—fi ewwrppsosesnszr-P D-O‘DDONOQOQD-D-Q-WQO’O-O‘D-O‘m released ADP water cellular respiration 103 25. sunlight 26. lactic acid 27. NADH, FADH2 28. glycolysis 29. hydrogen Appendix 08 Consent Form August 27, 2001 Dear Parents and Student, As students in Marlo Wiltse’s college preparatory biology course, you will be participating in assignments, activities, laboratory experiments, surveys, and assessments that have been developed as part of a Master’s thesis research project through Michigan State University. These items were created with the intent to improve the student’s comprehension of the material covered in this course. As part of her research, the instructor would like to be able to use the data collected from this class in the form of pre-tests, activities, surveys, homework assignments, and post-tests. The names of students will not be used in this thesis paper, as it will only include statistics and anonymous samples of written work. The privacy of the student will be protected to the maximum extent allowable by law. Every student will be required to complete all assigned work, but the research data will only consist of those who agree to have their work included. There is no penalty for a student who denies permission to have their work used as data; neither academic nor personal risk will ensue. However, the granting of such permission will be very appreciated by the instructor. If you have any questions regarding this research project, please contact the instructor, Marlo Wiltse, at (517) 541-5694. If participants have questions regarding their roles and rights as a subject for research, they may contact: David E. Wright, Ph.D. Chair, University Committee on Research Involving Human Subjects, (517) 355-2180. Sincerely, Mrs. Marlo D. Wiltse Name of student I GIVE permission for the data regarding my child’s class work in Mrs. Wiltse’s biology class to be used for her research thesis. Confidentiality of student and their data will be maintained. I DO NOT wish for the data regarding my child’s class work in Mrs. Wiltse’s biology class to be used for her research thesis. There is no penalty for choosing not to participate. Student Signature Date of consent Parent/Guardian Signature Date of consent 104 References l. Amone, M. -P. and Barbara Grabowski. 1991. Effects of Variations in Learner Control on Children’s Curiosity and Learning from Interactive Video. In: Proceedings of Selected Research Presentations, Annual Convention of the Association for Educational Communications and Technology. 24 pp. 2. Bender, Renet, and William Bender. 1996. Computer-Assisted Instruction for Students At Risk for ADHD, Mild Disabilities, or Academic Problems. Allyn and Bacon. Massachusetts. 166 pp. 3. Bennett Ph.D., Frederick. 1999. Computers as Tutors: Solving the Crisis in Education. Faben, Inc. Florida. 232 pp. 4. Borsook, Terry K. 1991. Harnessing the Power of Interactivity for Instruction. In: Proceedings of Selected Research Papers Presented at the Annual Meeting of the Association for Educational Communications and Technology. Florida. 16 pp. 5. Cuffaro, Harriet K. 1984. Microcomputers in Education: Why Is Earlier Better? Teachers College Record. 84(4): 559-568. 6. Geisert, Gene and Rita Dunn. 1990. Learning Styles and Computers. St. John’s University. New York. 14 pp. 7. Harper, Barry, John Hedberg, Bob Corderoy, and Robert Wright. 2000. Employing Cognitive Tools Within Interactive Multimedia Applications. In: Computers as Cognitive Tools: No More Walls. Susanne P. Lajoie, editor. Lawrence Erlbaum Associates, Inc. New Jersey. 227-245. 8. Hounshell, Paul B. and Stanford R. Hill, Jr. 1989. The Microcomputer and Achievement and Attitudes in High School Biology. Journal of Research in Science Teaching. 26(6): 543-549. 9. Jenkins, E.W. 1993. School Science and Technology: Some Issues and Perspectives. Centre for Studies in Science and Mathematics Education, University of Leeds. DFE/Welsh Office. 246 pp. 10. Lehman, Jeffrey R. 1989. Chemistry Teachers’ and Chemistry Students’ Perceived Advantages and Disadvantages of High School Chemistry Laboratories. School Science and Mathematics. 89(6): 510-514. 11. Lesgold, Alan. 2000. What Are the Tools For? Revolutionary Change Does Not Follow the Usual Norms. In: Computers as Cognitive Tools: No More Walls. Susanne P. Lajoie, editor. Lawrence Erlbaum Associates, Inc. New Jersey. 399-408. 105 12. Lu, Casey R., Burton E. V055, and Lewis J. Kleinsrnith. 1997. The Effect of a Microcomputer-Based Biology Study Center on Learning in High School Biology Students. American Biology Teacher. 59(5): 270-278. 13. Magin, DJ. and J.A. Reizes. 1990. Computer Simulation of Laboratory Experiments: An Unrealized Potential. Computers and Education. 14(3): 263-270. 14. Matray, Paul and Steve Proulx. 1995. Integrating Computer/Multimedia Technology in a High School Biology Curriculum. American Biology Teacher. 57(8): 511-520. 15. McMahon, J., J. Gardner, C. Gray and G. Mulhem. 1999. Barriers to Student Computer Usage: Staff and Student Perceptions. Journal of Computer Assisted Learning 15: 302-311. 16. Morse, Ronald H. 1991. Computer Uses in Secondary Science Teaching. Office of Educational Research and Improvement. Washington DC. 4 pp. 17. Robertson, E.B., B.H. Ladewig, M.P. Strickland, and MD. Boschung. 1987. Enhancement of Self-Esteem Through the Use of Computer-Assisted Instruction. Journal of Educational Research. 80(5): 314-316. 18. Savenye, WC. and E. Strand. 1989. Teaching Science Using Interactive Videodisc: Results of the pilot year Evaluation of the Texas Learning Technology Group. In: Proceedings of Selected Research Papers Presented at the Annual Meeting of the Association for Educational Communications and Technology. Texas. 20 pp. 19. Steinberg, Esther R. 1989. Cognition and Learner Control: A Literature Review. Journal of Computer-Based Instruction. 16(4): 117-121. 20. Tobin, Kenneth. 1990. Research on Science Laboratory Activities: In Pursuit of Better Questions and Answers to Improve Learning. School Science and Mathematics. 90(5): 403-418. 21. von Glasersfeld, Ernst. 1987. The Construction of Knowledge. Intersystems Publications, California. 347 pp. 22. Windelspecht, Michael. 2001. Technology in the Freshman Biology Classroom: Breaking the Dual Learning Curve. American Biology Teacher. 63(2): 96-101. 23. Ybarrondo, Brent A. 1984. A Study of the Effectiveness of Computer-Assisted Instruction in the High School Biology Classroom. Idaho Reports and Research. 20 pp. 106 General References 24. Johnson, George B. and Peter H. Raven. 2001. Biology Principles and Explorations. Holt, Rinehart, and Winston. 1096 pp. 25. Vernier Software, Inc. 107 lit'llitiltiltitl