4‘ «a '23-:- . . 384.1: ' ,~\ ‘ . » . , . . -. 1'. trig - 5‘- :J A" '.‘ 5 “ I2:"‘A—U‘x v. v: "‘ A 117. . ~‘9 $0331“: . ~‘ . \ 1‘: “flag, ”586$; . :53; 'r fa! “3.3%.?“ .i "a I _‘ .gfif‘.’ m " _'.L4X ) -... 1.151!“ m "“3319 02:2 ‘ . ‘ 1.; 31" f 4‘ x 5‘13??? I ‘11-. 3"» .3). g. nu; V f ‘ . :1 4‘“ H ‘_ \fi‘f-m‘”b'.‘{‘ 511‘,“ M. “a a)! “I r . > 1 . ‘ ‘ 1. ‘. . . V 5‘ . ~ , - - I “If: "if"; f ' a ‘J ”‘3‘? .1. ‘ ‘ '7‘. ‘ .- .u ' ‘ ""55 ‘ ' ' . :afi H ‘J I. P I 9. 3:: 1 ‘ 1&3? m “3:.“ u. ' 3‘s: w . ‘. 1m .1. - n. .1. , H”. u w... ‘ V ‘ 1."-A- ‘ . .u . 1 ”Wu.-. K" '1: . a >. :3. 7'! ' U vvy-n ... r. . MW": 5mm}: 3-, l . THE S" SPAR Win ”an if \ Itiiu'iifimmiumumw 3 1293 01022 25 This is to certify that the thesis entitled Modified Laboratory Activities for Cell Biology Used as an Introduction to High School Biology presented by Brian A. Webster has been accepted towards fulfillment of the requirements for MS degree in BiologicaJ_Sciences - W Major professor 3/3/94 Date 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution LIBRARY M‘Chigan State University PLACE ll RETURN BOX to roman this checkout tron your record. TO AVOID FINES return on or baton dut- duo. DATE DUE DATE DUE DATE DUE PDQ CHI [:3 ll [:3 J II I MSU to An Affirmative Adlai/Equal Opportunity Institution WW.‘ -— —— —- —‘ e .7 —- a“ MODIFIED LABORATORY ACTIVITIES FOR CELL BIOLOGY Used as an Introduction to High School Biology BY Brian A. Webster An Abstract of a Thesis Submitted to: Michigan State University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE Department of Natural Science 1993 ABSTRACT Evaluation of Modified Activities in Cell Biology used as an introduction to High School Biology. by Brian A. Webster The Modified Laboratory Activities for Cell Biology was used as a unit for a first-year biology course requirement for High School sophomores. The unit is tailored for students who have poor attendance, low test scores, and who are within a school having limited supplies and equipment. These labs twenty "hands on" cell biology laboratories pro- promote active involvement, and are geared for a wide range of student abilities and learning styles. Each activity enables students to discover and apprec- iate the study of the cells as an enjoyable and integrated part of their biology curriculum. These activities are easy to do and stimulate as well as entertain students while en- abling them to master basic skills. The materials for activities were readily available and inexpensive, and the laboratory format was condensed and mod- fied to fit the needs and interests of the students. The students' understanding of cell biology and its im- plementation was measured using a Pre-test, Post-test, along with an Evaluation Survey. As a result of the application of this unit, the students demonstrated progressively high scores as well as a desire to complete each task. ACEEQELEDEMEEIS Sincere appreciation must be expressed for assist- ance, support and encouragement provided by Dr. Clarence Suelter and Dr. Merle K. Heidemann. They first proposed the idea of implementing "hands-on" activities with an emphasis on cell biology. It is also necessary to men- tion the immeasurable benefits and varied experiences connected with the workshops in Molecular Biology and Environmental/Behavioral Biology, along with the Front- iers Program in Biological Science. My gratitude also goes out to my students, because without their patience and cooperation there would be no Cell Biology Unit. It was their work, dedication, and discipline that made this program such a success. I be- lieve in the philosophy that good students make good teachers. IAELE QE QQEIEHI§ Acknowledgments.........................................i Table of contents.......................................ii List of tables and figures. .................... -... ..... iii Chapter 1 Introduction.................................1 Chapter 2 Instruction..................................5 Outline of unit.....................................6 Analysis of activities..............................9 Chapter 3 Evaluation...................................20 Pre-test and Post-test..............................21 Attendance....... ....... ............ ............. ...34 Attitude survey.....................................39 Teacher observation.................................41 Chapter 4 Conclusion............... .............. ......42 Summary ............ ......... ....... ............. ...43 Plans for the future................................44 Appendix A - Laboratory activities......................45 Appendix B - Student test : Pre-test and Post-test......70 Appendix C - Attitude survey................... ..... ....77 Selected Bibliography....................... ...... ......79 ii 1- IAQLEfi 1. 2. 3. 4. Pre- Pre- Pre- Pre- LI§I QE IAELEfi LED EIQQB§§ and Post-test and Post-test and Post-test and Post-test 5. Attitude Survey 11- EIQHEEfi 1. Comparison of Pre- for each student 2. 3. 4. 5. 6. 7. 8. 9. Attendance: Before, During and After 10. Attendance: Before, During and After 11. Attendance: Before, During and After 12. Attendance: Before, During and After Comparison of Pre- for each student Comparison of Pre- for each student Comparison of Pre- for each student data data data data and Post-Test and Post-Test and Post-Test and Post-Test Item Analysis Item Analysis Item Analysis Item Analysis Unit Unit Unit Unit of Pre- of Pre- of Pre- of Pre- iii and Post-Test and Post-Test and Post-Test and Post-Test 2nd 4th 6th 7th 2nd 4th 6th 7th 2nd 4th 6th 7th 2nd 4th 6th 7th hour hour hour hour hour hour hour hour hour hour hour hour hour hour hour hour CHARTER]. Teaching at Redford High School, a high-risk, high- needs urban minority institution, served as an impetus for the development of this program. Problems that be- set the school in general, such as poor attendance, lack of interest and inadequate supplies, are also the pri- mary problems in the science classroom. Added to these problems is a very negative perception about studying science. To address these problems in sophomore biology classes, this program was developed to provide inter- active, hands-on activities that could be understood and completed within fifty minutes with minimal equipment and supplies. The labs were developed to pique the in- terest of even the occasional learner whose brief forays into the classroom were usually very ambiguous for the student. The problems attendant to lengthy laboratory act- ivities that required an extensive pre-lab, days to com- plete and a comprehensive lab debriefing are avoided in this approach. Also avoided is the nearly insurmount- able task of preparing for such labs, with their very expensive and extensive materials. What is not stud- iously avoided is finding ways for the students to be- come involved in "hands-on, minds-on activities" (Tobin, 1987) that appeal to their individual learning styles. Research in science instruction provides the basis for these ideas: Students who engage in activity-based instruction have more positive attitudes toward science. The more direct experiences students are given with concept development, the more successful they will be in comprehending the textbook material. Hands-on activity based instruction improves com- munication, computational and problem-solving skills. (Yager, 1991) The students involved in the testing of this prog- gram were sophomores at Redford High School. Each of the students has had one year of Fundamentals of Natural Science. Redford High School has a student population of over three thousand students, one hundred thirty-five teachers (thirteen science teachers) and another fifty administrators and support staff. The ethnicity of the students is 99% African Amer- ican. The remaining 1% are Caucasian, Asian, and His- panic. The students also come from socio-economically diverse families, with students coming from tradition- ally middle-class families to those families classified as low-income. The students are subjected to an anti-intellectual environment with high levels of violence evident. The focus of this program was to create interest in science, improve attendance and enhance achievement. The qualitative issue of interest was addressed by us- ing an attitude survey, administered before and after the unit. A significant increase in development of a positive attitude toward the study of science was evid- ent. A demonstrable improvement in attendance during the program had a carry-over effect into the next unit. The results on the pre- and post-tests showed the accumulat- ion of knowledge about this unit. What was less measurable was an increase in science process skills that influenced subsequent learning. This correlated with research that suggests guided in- quiry is the most successful mode of instruction: Have students use as many hands-on activities as possible to help them discover biological concepts for themselves. Provide students with an introduction to a concept and enough background information so they can work out the rest of the idea. Begin with the familiar and move toward the unfamiliar. (Gordon, 1990) 9mm; QEILIEE OE EEII EBE:IE§I 1. 2. 3. 4. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Microscope Making a cell Cheek cells Onion cells Osmotic imbalance Cell division Chromosome number Chromosome study DNA model Transcription and Translation Making Protein: Translation Protein Properties of enzymes Probability and heredity Sex-linked traits Crossing over Gene pool Dihybrid cross Trait survey Recombinant DNA EQ§121E§I EXALHAIIQE ANALYSIS QE LABORATORY ACTIVITIES The laboratory activities in cell biology are divided into five categories of study. 1. Cell structure and function 2. Cell division and reproduction 3. Chromosome and DNA study 4. Protein and enzymes 5. Genetics and heredity The labs within this unit are based on the Scientific Method and follow this format: I. Introduction II. Materials III. Procedure IV. Observations V. Analysis and Conclusion I. INTRODUCTION - In the introduction students are given background information on the activity that includes the purpose and the connections to prior learning. II. MATERIALS - The materials needed to do these activities are easily obtained: paper, rulers, glue, scissors, etc. Most are readily available household supplies. Other pieces of equipment such as microscopes, glassware, along with stains and dyes, may be obtained from a high school science lab. III. RROOEOORE - The procedure is briefly stated in a simplified manner. The step-by-step process involves five steps or less. This helps maintain the students' interest, keeping the students on task throughout the lab activities. IV. ORREREAIIOR - During the lab, the students are able to note changes that take place throughout the duration of the lab activity. Some labs require students to make drawings of what they observed, while others require a brief written explanation as to what they have witnessed. The students graph their data, if indicated, and compare their results with those of the other students in the lab. V. ARRLIRLS ARR OOROLORLOR - This section encourages stud- ents to answer questions and draw their conclusidns based on the results of the observations obtained from their activity. The laboratory activities are provided in Appendix A. LAB #1 MICROSCOPE The students in this activity were to learn the proper use of the microscope, a basic tool for the study of cell biology. The students worked in collab- orative units. Each group shared the responsibilities of gathering the materials: microscope, slides, cover- slips, newspaper and other samples. A brief pre-lab discussion consisted of a review of the parts of the microscope and its appropriate use. The proper method of preparing a wet mount was also demonstrated. The students were instructed to start their invest- igation by observing the letter "e". This was to be followed with attempting to read a word or phrase from the newspaper through the microscope. Upon mastery of the necessary locating and focusing skills, the students were free to investigate items such as make-up, hair strands and skin. A variety of preserved slides were also available for investigation. LAB #2 MAKING A CELL The purpose of this activity is to understand the structure and function of organelles in animal cells. Since many of these components are too small to be seen with the light microscope, a model cell was created us- ing food materials such as noodles, cereal and beans to represent the cellular organelles. The materials were 10 readily available for under ten dollars. They were placed in containers marked with the organelle they were to represent. Using a textbook diagram of an animal cell as a template, the students wrote their function next to the name of the organelle. LAB # 3 CHEER CELLS Students were given an opportunity to observe their own cells using the microscope. Telling students that the human body consists of billions of cells is not as effective as having them examine their own cells. The students were guided through the procedure of gently scraping their cheek cells in a preparation of a wet mount. The students were asked to sketch the structures they observed and to label them based on the "Making a Cell" activity. They were then asked to list which structures were in the textbook and in their model but that could not be seen under the microscope. LAB # 4 ONION CELLS Observing a plant cell under the microscope gave the students the chance to compare the structure of a plant cell with that of an animal cell. The Students prepared a wet mount of thin sections of onion. After observing and sketching what they saw under low and 11 high power, the students stained additional onion slides, using a demonstrated staining technique. The students again sketched and labeled what they observed. A brief written comparison of the effects of staining onion cells on visibility was also included. LAO # 5 OSMOTIC IMBALANCE The concept of transport through a cell membrane was presented to the students using examples from daily life. To reinforce these concepts, the students exposed plant cells to hypotonic and hypertonic environments. While waiting for the results, the students were asked to formulate an hypothesis about the outcome of their treatments. The students recorded their hypo- thesis and their final observations. They then sketched diagrams of the cells before and after treatment. The students were asked to describe the mechanisms that might be the explanation for their results. They were then debriefed to check to see that appropriate conclusions were made. LAB # 6 CELL DIVISION In this activity the students modeled the steps of mitosis using a variety of materials such as colored construction paper, yarn, toothpicks (donated by the school's art department). These materials were measur- ed, cut and assembled on a long sheet of construction 12 paper, to depict the cell parts and the role they play in the mitotic process. The students used a diagram of mitosis as their guide. They labeled their assembled construction as to the phases and the names of the individual components. Upon completion of this activity, the students viewed prepared microscope slides depicting the stages of cell mitosis. LAL #7 CHROMOSOME NUMBER The species specificity of chromosome number was evaluated in animals. A worksheet supplying inform- ation about chromosome number gave the students the opportunity to compare the number of chromosomes in different species and to speculate about their differ- ences. The unique nature of the chromosome number in plants was explored by looking at specific plants and their hybrids using seed catalogues. Students cut out pictures to make family groupings. The economic value of hybrids was then discussed with the students. They were asked to speculate about this process if it were to be applied to human beings. LAB #8 CHROMOSOME STUDY The students were introduced to the clinical lab- atory test of producing a human karyotype. 13 Students were given a sample simulating normal chromosomal distribution in the cell nucleus. They were directed to sort the forty-six chromosomes and to arrange them into homologous pairs according to their likeness in both shape and structure to produce a karyo- type. After matching chromosomes the students assembled and numbered their sequence. Pictures of human karyo- types with abnormalities were then given to the students to compare to their normal karyotype. LAB #9 DNA MOLECULE This lab permits students to learn how the nucleo- tides (phosphates, sugars and bases) are arranged in a DNA molecule. By using candies of different colors and joining them together with toothpicks the students were able to demonstrate how the base-pairing rule applies to the building of DNA. The students fitted "pick up sticks" through the outside phosphate groups (miniature marshmallows) for support. Twisting the sticks provided a clear illustr- ation of how the DNA is shaped into a double helix. LAB #10 TRANSCRIPTION To demonstrate transcription and translation, the students traced and cut out the DNA components from colored construction paper, using the same colors used 14 in the DNA candy lab. Students constructed the RNA strand from the DNA code spelled out on the lab sheet. The tracings were assembled, labeled and glued on a sheet of paper. The students made their observations, then answered the questions pertaining to the shape of the DNA/RNA molecule. LAB #11 MAKING PROTEIN: TRANSLATION This lab is basically a follow-up activity work- sheet showing how DNA and RNA are involved in the making of protein. The previous laboratory demonstrated how the message in DNA is transferred to m-RNA. The stud- ents in this activity fill in the missing pieces of the puzzle needed to code the specific amino acids to form protein. The order of events in the building of protein were diagrammed and discussed prior to doing this activity. LAB # 12 PROTEIN This is a standard laboratory investigation in which diverse materials are tested for the presence of protein using nitric acid staining. The students place materials in test tubes and added drops of nitric acid to the test tubes of each sample being tested. The students recorded their obser- vations, determining whether the materials contained protein. 15 LAB #13 PROPERTIES OF ENZYMES In the pre-lab, the students were briefly exposed to the concepts of enzymes, substrates and catalysts. Liver contains the enzyme peroxidase. Peroxidase breaks down hydrogen peroxide into water and oxygen gas. Based on this information, the students were asked to hypoth- esize what if any effect altering the liver would have on its peroxidase activity. The students placed liver, fresh, ground and boil- ed, into separate test tubes filled with two milliliters of hydrogen peroxide. They then rated the results from zero (having no bubbles) to ten (having the most activity). The students recorded their results. Many students were able to explain the observed differences and draw conclusions. LAB #14 PROBABILITY AND HEREDITY The purpose of this activity is to give students an understanding of what is meant by probability and how it plays a role in determining the outcome of visible phy- sical traits. The necessary genetic terms were introduced as well as the diagraming of a Punnett's square. From this, questions were raised concerning how different traits such as eye color might be passed on from generation to generation. 16 The activity of flipping coins to determine probab- ility reinforced the concept of chance. LAB #15 SEX-LINKED TRAITS The pre-lab consisted of a review of the concept of sex-linked inheritance. Having already explored the role of probability in regard to autosomal inheritance in the previous lab, the special situation of sex-linked inheritance was covered. The students marked pennies. The one penny represented the egg cell and was labeled XM on one side and Xm on the other side. The penny representing the sperm was marked Y on one side and XM on the other side. The capital "M" on the chromosome is for a normal gene and the small "m" expresses the mus- cular dystrophy gene carried on the X chromosome. This procedure assumes neither parent has the condition. The students flipped the coins 48 times, then tal- lied their results on the chart under the observation section of the lab sheet. The students were then given a list of linked traits (i.e. baldness, color blindness) and asked to ex- plain why their results showed a higher incidence of these traits in males. LAB #16 CROSSING OVER The students were introduced to the concept of meiosis and the possible exchange of homologous Chromo- 17 somes. The chart diagramed on the lab sheet represented the crossing over points of seven genes on the homolog- ous chromosomes of a fruit fly. The alleles were (A-G) on the one chromosome and (a-g) on its homologue. Students rolled the dice. This number obtained would indicate the point of crossing over. The genes that were present on one chromosome (A-G) were switched at a location point on the adjoining chromosome (a-g). For example, point three might be shown as ABCdefg. The students rolled the dice a set number of times and then tallied their results on the data table. Ques- tions based on the activity were completed. LAB #17 GENE POOL The purpose of this activity is to simulate a gene pool, by demonstrating how the mixing of genes affects a population. The students were given instructions in the pro- cedure to form two piles of fifty each, containing” thirty-five B: fifteen b. These were written on small pieces of paper to represent brown and blue-eyed in- dividuals. One pile represented males and one represented females. Assuming each pairing resulted in one child, it was possible to determine the genotype of the children. It was the students' responsibility to randomly 18 select one piece of paper from each pile and to create a genotype. The students were to complete this task 49 times, as outlined in the procedure, then divide their pair totals by 50 and multiply by 100. They were then able to calculate the percentages of the two alleles for eye color in that given population. The students were asked to critique this procedure and to list the variables of what would keep this match- ed system from working i.e. death, infertility, choosing not to reproduce, etc. LAB #18 DIHYBRID CROSSES This activity demonstrated the F one generation in a dihybrid cross with 2 alleles at each gene site. They were to simulate a dihybrid cross by using paper as flags on toothpicks. The flags represented the 2 gene traits and their alleles. The allele combination: BC, Bc, bC, be of the sperm and egg cell were discussed at onset of this activity. The students were responsible for placing the sex cells, male and female, into a Punnett square. They were then asked to predict the genotype ratio of each offspring. Punnett squares with labels across the top and along the side for the paired genes BC, Bc, bC, bc were provided. Completing the Punnett square made it possible to determine the ratio of each genotype. 19 LAB #19 TRAIT SURVEY Performing a survey to determine the frequency of dominant and recessive traits within a small population demonstrates a trait survey. Students were given a list of detailed physical traits, evaluated themselves for these traits and completed the worksheet provided as part of the lab sheet. The individual data were compiled and presented to the students as a class survey. The students then graphed the results. LAB #20 RECOMBINANT DNA The students modeled the techniques used by scient- ists in the technology of forming recombinant DNA. Prior to doing this activity the students were given an opportunity to assemble a DNA molecule (Lab #9) using the base-pairing rule. In this activity students were asked to cut out segments of new DNA and splice in the complementary seg- ment to the blank segment on the Circular plasmid model. Performing such recombinant DNA techniques gave students an understanding of how bacteria (Escherichia coli) can be given the genetic information for proteins and used to produce hormones and other substances. CHARTER}. 20 21 w AND Lil—.03 " EST A Pre-Test and Post-Test of the same twenty questions was administered before and after exposure to this unit. This test is found in the appendix B. The students as a whole demonstrated a considerable im- provement in performance on these questions. The students apparently developed a better understanding of the material during this "hands-on" Cell Biology Unit than through a lecture based format. The improvements ranged from 5% to 70% as shown in (Figures 1-4). The trend seen in these figures strongly supports the supposition that clearly-demonstrated increases in learning would be seen with this method of teaching. 22 Table 1 PRE- AND POST-TEST DATA: 2ND HOUR 'an-Tzsr posr-rssr STUDENT INDIVIDUAL scone % STUDENT INDIVIDUAL scone z 1_rw__w. 30 ' 1 20 100 {2 60 i 2 a 40 u 3 i 3 12 60" 4 f 4 8_ 40 . s E 5 15 75 6 z 6 a 40 i 7 i 7 17 65 i a i a 14 70 I 9 g 9 14 70 f 10 g 10 16 60 l E 11 I 11 15 75 y i 12 12 14 70 j E 13 , 13 14 70 I ; 14 f 14 9 45 I ! ' 15 16 60 I L i 16 15 75 J urns = 6.5 32.54 urns = 13.4 67% non: = 6.0 304 won: a 14.0 70* :::CQ”=- 2:3-12.0 23:60 a :igégns- :f0220.0 133100. 23 Table 2 PRE- AND POST-TEST DATA: 4TH HOUR PRE-TEST POST-TEST STUDENT INDIVIDUAL scone : STUDENT INDIVIDUAL scone s [F 1 12 F—GO—fi 17 35 2 7 35 2 e 30 3 7 35 3 17 85 4 a 40 4 9 45 5 9 45 5 10 50 6 12 60 6 17 85 7 11 55 7 1s 75 a 6 30 a 9 45 9 9 45 9 10 50 n 10 5 25 10 9 45 H 11 10 50 11 14 70 fl_‘ 12 6 30 u 12 11 55 u 13 14 70 u 13 17 85 “A. 14 8 40 14 16 80 u 15 9 45 15 11 55 u 16 6 30 16 15 75 H 17 10 50 17 12 60 u 18 7 35 1a 17 85 u 19 a 40 19 11 55 n 20 7 35 17 3—:— MEAN = 8.5 42.5% MODE = 7.0 35% MEDIAN = 8.0 40% RANGE = 5.0-14.0 25-70% 71% 85% 85% 30-85% 24 Table 3 932- AND POST-TEST DATA: 6TH noon pas-735? POST-TEST STUDENT INDIVIDUAL scone 4 STUDENT INDIVIDUAL scone 4 =1 3 15 1 10 50 2 7 35 fl 2 15 75 3 7 35 fl 3 17 65 4 6 40 fl 4 10 50 5 5 25 u 5 14 70 6 12 60 6 20 100 7 9 45 H 7 19 95 6 5 25 6 17 65 9 11 55 H 9 13 65 10 14 70 u 10 19 95 11 11 55 l 11 20 100 12 3 15 H 12 6 40 n 13 11 55 u 13 ' 19 95 14 6 30 14 15 L;:5__ NIAN = 6.0 404 MIAN = 15.3 76.54 MODE = 1 . 554 N00: = 19.0 954 NIDIAN 7.5 37.54 MIDIAN = 16.0 604 RANGE 3.0-14.0 15-704 NANCI = 6.0-20 40-1004 25 Table 4 PRE- AND POST-TEST DATA: 7TH HOUR EEEIIEEI POST-TEST STUDRNT INDIVIDUAL SCORE 4 STUDENT INDIVIDUAL scone 4 1 9 45 1 20 100 H 2 4 20 2 16 60 3 6 30 3 9 45 4 6 40 4 13 65 5 10 50 5 20 100 6 12 60 6 16 60 7 5 25 7 10 50 L 6 9 4s ’ 6 16 60 n 9 4 20 j 9 19 95 10 4 20 i 10 6 40 11 7 35 i 11 19 95 n 12 4 20 I 12 17 65 n 13 6 30 E 13 11 55 u 14 7 35 i 14 13 65 H 15 4 20 i 15 15 75 H 16 2 10 E 16 15 75 17 10 50 i 17 19 95 NIAN = 6.5 32.54 NIAN = 15.6 794 MODE = 4.0 204 N00: = 20.0 1004 NSDIAN = 6.0 304 MEDIAN = 16.0 604 RANGE = 2.0-12.0 10-604 RANGE = 6.0-20 40-1004 26 l 25.83 .60 .6. 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INCI=I N SI .800“ ILL? 34.1““ 83.1.3' ONV Dfllllnfl '380339 333WGN3JJN 0| alnbyg (I QI SI ll '- ’0 .1... —“ ’—U .—~ MEICSIIIU!.ap u ”"613 1313' bntjna 010:3. 333NV0N3L¢V _U SI '380138 331"“ USLJV GNV DNIHHG 800" “$9 (I 9| 38 MDOIRMI’ .~ .0 .u .a .u .u .u .u .. .e .o .0 .e o o o 0 ~ u a o u u u ' a r u. a u u u u n u an . . .. . . — e e 9.. e..e F_. .=0 —.e — a .7: ..u a... a._: u.,- a... » a a a... u_,u a .7: a : 6.7: a... a . u u o u G u I a .6 .. .~ .. .o .u .0 .~ ud=0224u I u Damon. a u acnpaa ’ n ’nnon whocno -n ’édm20’2nnu unwonm. 002.20 >20 ’fifimz c2.du «a: 20:2 39 ATTITUDE SURVEY When asked to respond to a series of twenty qualitative questions about the Cell Biology Unit, the students were uni- formly positive in their responses. The questionaire is found in appendix C. The questions gave the students an opportunity to eval- uate the unit. More than seventy-five percent of the res- ponses on the survey were quite in contrast to the usual re- frain of the work being too boring, too hard, and too mean- ingless. There is a chance that their positive responses were enhanced because they were being asked. 40 Trabflja 5 INFTITTHNE sumuniy BLIIIE EQALI: STRONGLY AGREE 5 AGREE SONEWHAT 4 NEITHER AGREE NOR DISAGREE 3 DISAGREE SOHEWHAT 2 STRONGLY DISAGREE 1 1mm EIBIEHIII 5 % 4 % 3 % 2 % % 1 38 49 33 42 6 9 0 0 O 2 47 61 16 20 9 11 3 3 3 3 46 59 24 31 3 4 4 5 . 2 4 38 49 28 36 7 9 3 3 .2 5 43 55 25 32 3 4 3 3 3 6 4O 51 25 32 8 10 O O 3 7 42 54 23 29 8 10 2 2.5 .5 8 25 32 25 32 11 14 10 12 9 9 28 36 16 20 14 18 10 12 11 10 47 61 19 24 3 4 3 3 5 - ._l___1__1.___1—J__L_1 41 TEACHER Q§§EBVATION The students worked in pairs to complete their act- ivities. A majority of students made an effort towards the success of this program. The students appeared to enjoy doing "hands on" activities, opposed to that of a written busy-work assignment. It was shown also that students were able to master basic skills, illustrated in the comparison between the Pre-Test and Post-Test administered at the be- ginning and end of the unit. There was also a signifi- cant improvement in the students' attendance, which was taken daily. The attitude survey that was provided at the end of the unit clearly showed a positive response, as indicated in the rating Survey Evaluation given at the end of this unit. m& 42 43 §EMMABX The cell biology program developed and tested in this study was created to realistically deal with the science classroom problems of disinterest, poor attendance and limit- ed supplies. The emphasis on short, hands-on activities engaged the interest of the learners. In fifty-minute classes it was possible to introduce a topic, complete an activity and de- brief the activity. This packaged approach reduced the frustrations felt by both the student with consistent atten- ance and the occasional student whose brief forays into the classroom are frequently disruptive. Attendance became less of a confrontational issue and more of a "do what we are doing while you are here" situa- tion. The net result was improved attendance. The basic, inexpensive materials needed for the activ- ies simplify the almost insurmountable task of finding suffi- cient materials for the students. A lateral effect of this was the inclusion of more activities on different topics and the establishment of hands-on learning stations. The net result of this project was a workable approach to current classroom problems and a revitalization of my bio- logy courses. 44 ELAES £93 THE'EHIHBE The very positive results in the three areas of interest, attendance and learning make it evident that the rest of the units must be adapted to involve "hands- on" activities using the same general approach. Also, since these activities required minimal mat- erials and moderate amount of instruction, this is not an insurmountable task for the teacher. There was also the joy involved in watching classes form cohesive, cooperative learning units, interested in their tasks. WA 45 46 219.21.213.12 WW LQB mm BY Brian A. Webster 47 MICROSCOPE IEIEQQQQILQE: With the invention of the microscope, biolog- ists were able to see smaller and smaller objects. A light microscope can magnify an image several hundred times. A light micro- scope directs a beam of light through a spec- imen. An electron microscope uses a beam of electrons to magnify 100,000 times more than the naked eye. uAT§31AL_: light microscope microscope slides cover slip scissors newspaper 239932233: 1. 2. 3. Prepare a wet mount of a lower case letter "e" from a piece of newspaper. Place the wet mount of the letter "e" onto your microscope stage. Position the slide on the stage so the "e" faces you as it would on a newspaper. Observe the letter "e" using low power on your microscope. Focus the "e" with the fine adjustment. OBSERV T NS: AEALXfilfi AER QQEQLH§IQE: 1. 2. How did the "e" appear when you put the slide on the stage? How did the "e" appear through the low and high power objective? Was there a difference? 48 MAELHQ A SELL IEIBQQQQIIQN: Your body is made up of skin, blood, bones and muscle. All these parts are made up of smaller living units that are too small to be seen with the naked eye. They are called cell . Each cell in an animal or plant lives its own life while at the same time enabling the body to go on working. ngzgglggg: food materials: kidney beans pasta of different shapes kid's cereal EBQQEDQB§= 1. By using different food materials that resemble cell parts, assemble a plant cell. QE§EBEAILQE§= BLAKE EAST E992 EAIEBLAL MAJQB EHEQILQ! 1. nucleus 2. cytoplasm 3. cell membrane 4. cell wall 5. chloroplast 6. mitochondrion 7. endoplasmic reticulum 8. ribosomes 9. lysosome 10. vacuole 11. microtubules 12. centrioles AHAX§l§ AND QQEQLH§19H_= 1. Label the parts of a plant cell. \ lgfi 49 QEEEK QELLfi inzggnggzlgn: Cheek cells are typical of all animal cells and have a nucleus, cytoplasm and cell membrane. MAIEBLALfiz microscope coverslip microscope slide tooth picks medicine dropper iodine stain pencil paper EBQQEDHBE= 1. Place a drop of iodine stain on a clean microscope slide. 2. Gently scrape the inside lining of your cheek with the flat end of a clean toothpick. 3. Stir the material from your cheek into the drop of stain. 4. Cover the material with a coverslip. 5. Using low power, examine it under the microscope. QESERVAIIONS: AEALX§1§ AER QQHQLH§19H_: 1. Do the cells all have similar shapes? Are they all about the same size? 2. Label and describe the observed parts of the cell. 50 ONION CELLS LHIBQQQQIIQ_: Plant cells contain many structures found in an MATERIALS: EROQEDURE: animal cell. The most obvious difference between the plant cell and the animal cell is the size of the vacuoles. Vacuoles in both plants and animals act as storage areas. Plant cells also have a thick, firm, outer boundary called a cell wall. This outer boundary supports and protects the cell. microscope paper towel coverslip medicine dropper forceps iodine stain onion section pencil microscope slide paper 1. Slice a raw onion and cut one of the rings into one-centi- meter sections. 2. Peel the thin layer of cells from the inner curve of the onion section. 3. Place this thin layer in a drop of water on a microscope slide. 4. Add a coverslip and examine the slide under low power. 5. Place a drop of iodine stain on one edge of the coverslip. 6. Place the edge of a paper towel at the other edge. QfiSERVATlONS: ANALYSIS AND CONCLUSIONS: 1. How are the onion cells and animal cells alike? 2. Does each cell have a nucleus? cytoplasm? 3. What do you notice in the vacuole in the onion cell? 51 Qfiflgilg IMEALANQE IHIBQQQQILQE: What would happen if a cell were placed in pure water? The concentration of water outside the cell would be greater than inside a cell. More water molecules would enter the cell than would leave a cell. The cell would swell up and eventually burst if the water movement does not reach a balance. The reverse of this placement in a hypotonic solution is to place the cell in a hypertonic salt solution. The opposite is expected to occur. MAIEBIAL§= microscope eye dropper slide Elodea leaf coverslip EBQQEDHB§= 1. Make a wet mount of an Elodea leaf in tap water. 2. 6. Observe the cells under the microscope. Locate a single cell along the edge of the leaf. Then, make a 6% salt solution (6 g of salt dissolved in 94 ml of distilled water). Use this solution to make a second wet mount of another Elodea leaf. Let this wet mount stand for 5 minutes. Qagzgygzlgug: Draw a diagram of one cell from each slide. (Notice chloroplast positions) 1A2 EAIEB §ALI ELIEB (hypotonic solution) (hypertonic solution) ANALlfilfi AND QQNQLQ§IQE_: 1. Which cell do you think is in osmotic balance and which one is not? 52 QELL Elylfilgfl INTRODUCTION: Cells form new cells by a process called mitosis or cell division. During mitosis, one cell divides in half to form two new cells (daughter cells). Suppose you could watch a cell divide. You could see that the cell parts called chromosomes (rod-shaped structures) move around the cell during mitosis. Because chromosomes move in a particular way, you could arrange the events of mitosis into several steps. MATERIALS: construction paper - 4 colors scissors glue black yarn black thread toothpicks metric ruler PROCEDURE: 1. Study the steps in mitosis as outlined. Stages of Plant Cell Mitosis original chromosome Stop 1 Stop 2 . New Cells cell wall doubled chmnmomos coov chromosome Interphase Prophase Metaphase Anaphase Telophase 2. Use the materials listed below to represent the cell 53 2. Use the materials listed below to represent the cell parts. Cut the pieces of paper, yarn and thread to the sizes given in the table. CELL BABE MAIEBIAL filZE NHMLLB Cell wall and Blue paper 14 by 8 cm 5 membrane Cytoplasm Orange paper. 13 by 7 cm 5 Nucleus Purple paper 5 cm circle 3 Nucleolus Green paper 1 cm circle 1 Chromosomes Black yarn 4 cm long 20 Fibers Toothpicks Full size 24 Cell wall bet- Dark paper 1/2 by 8 cm 1 ween new cells Nuclei Thread 1/2 m 2 3. Start building the models of cell division steps by gluing each cytoplasm paper to the top of a cell wall and mem- brane. The cell wall and membrane should show on all sides. 4. Make each of the cell wall-membrane-cytoplasm pieces into a mitosis step. 5. Use glue to attach the proper parts to the pieces. ANALX§I§ AND QQNQLQSIQN: 1. Describe what happens in each step of mitosis. a. Interpahse: b. Prophase: c. Metaphase: d. Anaphase: e. Telophase: 54 SHEQMQfiQME NDMBEB INTRODUCTION: Every living thing has a certain number of chromosomes in all its body cells. of chromosomes is different from species to species. The number of chromosomes in body cells is called ohromosomo rumor. MATERIALS: organisms and their chromosome number pencil 239222235: 1. Study the list of organisms and their chromosome number. QBQANIfiM. QHBQMQEQME HQ; QBQANISM QEBQMQfiQME HQ; white ash 46 turkey 82 cattle 60 corn 20 dog 78 grasshopper (sp.1) 24 guinea pig 64 hydra 32 human 46 QBEEBEAIIQE§= ANALX§I£.AND QQNQLHSIQN§= 1. Which organism has the 2. Which organism has the 3. Do any organisms have the same chromosome number? If so, which ones? 4. Is there any relationship between chromosome number and the size of the organism? 5. Why is it that two species may have the same chromosome alligator 32 cat 32 tobacco 48 rose 14 rhesus monkey 42 pigeon 80 marijuana 20 horse 64 grasshopper (sp.2) 24 most chromosomes? fewest chromosomes? number but not resemble each other? The number 55 C ROM 80 §IQDX INTBQQQQTIQ_: The 46 chromosomes in your somatic (body) cells actually are 23 matched pairs of chromosomes. (23 multiplied by 2 = 46). Matched pairs of chromosomes are called homologous chromosomes. This collection of match chromosomes is called a karyotype. This provides a way to check for chromosomal abnormalities. A normal human karyotype is being prepared. Abnormal karyo- type will be displayed for comparison. MAILBLALfi‘ paper pencil scissors tape 1. Cut out each chromosome from sheet with scissors. 2. Match chromosome pairs by size and shape. 3. Arrange pairs of chromosomes in sequence from longest to shortest as shown below. 4. Tape and number homologous chromosomes under the obser- vation section . = % Q§§EBEAIIQH_' ‘:~P K ‘L ANAX§_§ AND _QNQLQ§lQ_= 1. What is different about the karyotypes supplied in class and the karyotype you prepared? 56 DNA MQDLL INTBQDQQTIQ_: A DNA molecule looks like a twisted ladder. A DNA molecule is made up of two chains of sugar groups and phosphates connected by pairs of nitrogen bases. There are four nitrogen bases; adenine A, Thymine T, Cytosine C and Guanine G. A connects to C, C connects to G. MATEgIAL_: Assorted color candy pieces Miniature Marshmallows Toothpicks Pick up sticks 239232233: 1. Using toothpicks, join the nitrogen bases together; 3 A's (green candies), 3 T's (orange candies), 3 6'8 (blue candies), 3 C's (red candies), following the base-pair- ing rule. 2. Arrange the sugars (black candies) and phosphates (minia- ture marshmallows) along the two sides of the DNA mole- cule. 3. Fit the pick-up sticks through the phosphates (miniature marshmallows) for support. 4. Complete by twisting the DNA molecule into a double helix. OESEBVATIONS: ANALX§1§ AND QQNQLH§IQH_= 1. What chemical make up the sides of the DNA molecule? 2. What nitrogen base always pairs up with A? G? 57 IRAN§QBIEIIQN AND IBAN§LAIIQN INTROOOOTION: Proteins are molecules needed by each and every cell in your body. An exact copy of the code for each protein, RNA, must be made from the DNA. The process by which the DNA code is copied onto a strand of mRNA is called tggng- g;ip;i_n. The process of building a protein molecule according to the code in mRNA is called translation. Two step process: DNA yields mRNA; mRNA yields protein. NATERIALO: construction paper glue scissors 1. Trace the bases, phosphates and sugars. EA)ETiUi|P| DI‘R.’ l G > E C ’ 2. Make a stencil by cutting out each shape. 3. Use the stencils to draw shapes on the construction paper. You willl need the following numbers of each unit. 2 Guanine G (blue) 2 Uracil U (purple) 2 Cytosine C (red) 6 Deoxyribose sugar D (yellow) 4 Adenine A (green) 6 Ribose sugar R (white) 2 Thymine T (orange) 12 phosphates P (black) 4. Use the appropriate pieces to construct a strand of DNA with the following base code: C, G, A, T, T, A 5. Use the remaining pieces to contruct a strand of mRNA that is complementary to the DNA strand. 6. Glue the pieces together on a brown sheet of paper. QLSEBEAIIQN_= ANALXSIS AND QQNQLQ§L9N3 1. How do the shapes of bases in the strand of DNA determine the order of bases in the mRNA strand? ODU 1. Use the parts. 58 NANINQ EBQIEL_= IEAN§LAILQN Proteins such as enzymes that control chemical changes in the body are made up of chains of amino acids. Each group of three bases in a molecule of DNA stands for a certain amino acid. This DNA code transcribed to mRNA (see previous exercise) and which moves from the nucleus to the cytoplasm. The code carried by the mRNA is used to arrange the amino acids in a particular order in the making of protein. pencil table - mRNA codes for amino acids information in the table to fill in the missing QBDEB QE EA§E§ : OLDER QE LA§E§ IN mRNA : ANINQ AQID§ CAT G T AA TARLR - mRNA codes for amino acids GUA valine CCA proline UCA serine UGU cysteine CGU arginine UUA leucine ACC threonine CAC histidine UUC phenylalaine AUU isoleucine QE§EBNAIIQN§= ANALX§1§ AND QQNQLN§19N_= 1. What are proteins formed from? 2. What are the roles of mRNA and tRNA in the formation of proteins in a cell? 59 EROTEIN INTRODUCTIO : One of the most important compounds in living things is proteins. They are molecules needed in living things for growth and repair of body parts. A simple test can be performed to det- ermine if a material has proteins in it. If you add nitric acid to a material, the color yellow will indicate the sample contains protein. When yellow fails to appear, very little protein is present. MATERIALS: Samples - cotton, paper, fingernail clippings and EBDQEDDN§= hair test tubes (5) labels (5) medicine dropper chemical compound - nitic acid 1. Label (5) test tubes for each material you test. 2. Place a small sample of each material in each test tube. 3. Using a medicine dropper, add (5) drops of nitric acid to each test tube. (Do not spill, due to staining) DDDEBYAIIQN§: DANELED Write down the results of each test. RESULTS Test tube #1 Cotton Test tube #2 Paper Test tube #3 Fingernail Test tube #4 Hair Test tube #5 peanut ANALIDID AND QDNQLDDIDNS: 1. What do you think would happen if you tested meat or other protein-containing foods? 60 ENDEEBILED DE AN ENLXNE INTROOOOTION: Enzymes are protein molecules that act as catalysts to speed up biochemical reactions. The enzyme pezoxigase speeds up the breakdown of hydrogen peroxide, a toxic by-product of cell metabolism, into harmless water and oxygen. MATERIALS: 3 test tubes 400 ml beaker test tube rack 3 % hydrogen peroxide forceps mortar and pestle EBDQEDDBE= 1. Set up 3 clean test tubes in a test tube rack. Pour 2 ml of hydrogen peroxide into each test tube. 2. Half fill a 400 ml beaker with water and put on the hot plate to boil. 3. Add a small cube of fresh liver to the first test tube. 4. Grind another piece of liver with some fine sand in a mortar and pestle. Use a spatula to transfer the ground liver to the second test tube. 5. Using forceps, put a piece of liver into the boiling water bath. Boil the liver for about 2 minutes. Remove the liver with forceps and drop into the third test tube. ORSERVATIONS: Describe the activities that took place within each of the 3 test tubes being tested. ANALXDID AND QDNQLD§19N§= 1. How do you explain the differences in activities between whole liver and ground liver? 2. What is the effect of boiling the liver on peroxidase activity? 61 PROBABILIT! ANQ EEREQITY INTROOUOTION: ProbaQiIity is the law of chance. A simple example of the laws of chance is tossing a coin. The coin can turn up either heads or tails. Both are equally likely. Therefore the probability of it being heads is half and the probability of it being tails is half. If you toss two coins, the situation is a little more complicated. This experiment will show that complication. MATERIALS: (2) pennies pencil paper ENDQEDDBfiz 1. One person should flip the two coins at the same time. The other person records the outcome on the data table. 2. Repeat step (1) until you have completed (4) flips. 3. Repeat step (2) until you have completed a total of 50 flips. OBSERVATIONS: TOSS COMBINATIONS RESQLTS COUNT TOTAL BOTH HEADS HH ONE HEAD;ONE TAIL HT BOTH TAILS TT ANALX§L§ AND QQNQLD§19_= 1. What is your ratio of toss combinations for HR : HT : TT ? 2. What biological processes are represented by flipping and pairing the two coins? 62 §EX:LINKED IBALID INTROOUCTION: If a trait is sex-linked, the genes are located on the X chromosome. A heterozygous female (XM,Xm) has a (50/50) chance that her egg cells will receive either an (XM) or an (Xm) during meiosis. Normal males have only one gene (XM) present. The chances of the sperm cells re- ceiving either XM or Y during meiosis are (50/50). You can determine the offspring of the cross (XM,Xm) and (XM,Y) by coin tossing. MATERIALS: adhesive tape pennies EBDQEDDEE= 1. Put adhesive tape on two pennies. 2. Mark one penny to represent the possible egg cells. Mark one side XM and the other side Xm. Mark the second penny to represent the possible sperm cells. Mark one side XM and the other side Y. Toss both pennies together 48 times. Use slashes to indicate the combinations that result after each toss. Total the results of each genotype and record them in the table. DDDEBNAIIDN§= OFFSPRING OFFSPRING RESULT OF TOTALS PHENOTYPE GENOTYPE EACH TOSS OBSERVED Normal female XM,XM or XM,Xm Female with muscular dys- tropy Xm, Xm Normal male XM,Y Male with musc- ular dystrophy Xm, Y ANAIDID AND QQNQLNDIQNS: 1. If a trait is sex-linked, how many genes for muscular dystrophy must a female inherit to have the disease? INTRODU : 63 QROSSING OVER Crossing over is the exchange of parts between two homologous chromosomes. During meiosis, two chromatids (duplicated chromosomes), one from each homologous chromosome, twist around each other. As they twist, the chromatids often break and the broken ends may switch places. This exchange of genetic material is called crossing over. Each pair will be heterozygous (different alleles) for the given trait, to supply clear and informative results. mm: paper pencil dice ENDQEDNNL= 1. Study the pair of chromosomes from a fruit fly. The fly is heterozygous for each of seven traits, a through 9, found on each chromosome. CROSSINGOVER POINTS ammonium» ~Jmcn¢uhhoH ~Jmtn¢uonaw ommaotrm Numbers 1 through 6 represent points at which crossing over may occur. For example, if a crossover occurred at point 3, the alleles on chromosome 1 would be abcDEFG. The alleles on chromosome 2 would be ABCdefg. Roll the dice, using the number that comes up as a cross- over point. Record this information as a tally mark in the data table. Repeat step 3 another 99 times. Calculate the percentage of the time each allele is found on the same chromosome as a. Record this information in the data table. 64 QD§EBEAIIQN§= DATA TABLE Number of times a Percentage of times is on the same a is on the same chromosome as chromosome as b b c c d d e e f f 9 9 ANALX§I§ AND QDNQLDDIQNS: 1. Is the location of crossing over more or less random, or does it occur more frequently in any particular location? 2. Which recessive allele most often ends up on the same chromosome as a? 3. Which recessive allele is separated most often from a? 4. Assume a crossover occurs at point 2. What would be the order of alleles on the resulting chromosomes? 65 SEND EDDL INTROOEOTION: Scientists have found that living things in a population may change over time because of changes in their genes. All the alleles for a trait of a certain population can be thought of as if they were together in a pool. Changes that take place in the alleles of individuals will slowly change the gene pool of the whole population. MATERIALS: sheet of paper pencil PROCEDURE: 1. Cut out 100 pieces of paper. 2. Separate into two piles of 50. 3. Label dominant (B) on 35 pieces of paper and recessive (b) on the other 15. B and b are the alleles for a particular gene. 4. Pick one piece of paper from each pile. 5. Repeat step (4) 49 more times. OESERVAIIONS: DATA TABLE 2ND DD QNL D1 9ND D IND DD PAIR TALLY PAIR TOTAL ANALXSIS AND CONQLUSION : 1. Determine the percentage of genotypes in the population. 2. How would this affect the population? 3. What factors affecting this process are not considered in this methodology? 66 DIHYERID CROSSES INTROOECTIO : A dihybrid cross involves two selected traits: brown eye color (B) is dominant to blue eye color (b); curly hair (C) is dominant to the recessive straight hair (c). Assume that a brown-eyed, curly-haired man and his wife, also with brown eyes and curly hair, plan to have children. They are both heterozygous for both traits and carry alleles for blue eyes and straight hair. MAT RIALS: paper pencil toothpicks (8) tape RROOEDURE: 1. Tape a flag to each of the (8) toothpicks. 2. Label the flags: sperm - BC, Bc, bC, bc egg - BC, Bc, bC, bc (Each toothpick represents a chromosome and each flag re- presents alleles for each of the two genes in question on the chromosomes) 3. Place flagged toothpicks in circle diagrams. 4. Arrange (4) sex cells for the male and (4) sex cells for the female into the punnet square. 5. Fill in the squares on your Punnett square with the genotype for each offspring. OBSERVATIONS: PUNNETT SQUARE ANALYSIS ANS CONCLUSIONS: 1. What is the phenotype ratio of this dihybrid cross? a. Brown-eyed and curly-haired b. Brown-eyed and straight haired c. Blue-eyed and curly-haired d. Blue-eyed and straight haired ODUC O : 67 TEAL! 3U VEY There are many traits in which dominant and recessive alleles are involved. For instance, the brown eyed allele is dominant over the recessive blue eyes allele for the generic trait, eye color. In hair color, black or brown genes are dominant over red and blond genes, while by itself the red gene dominates the blond gene. Curly hair or wavy hair genes are dominant over straight hair genes. Un- attached earlobes and the ability to roll your tongue are also dominant traits. By making a sample survey we can learn more about the different kinds of individual traits within our population. MATERIALS: trait tally sheet pencil EBDQEDDNE= 1. Count the number of students in your class who possess each of the traits listed. 2. Write this number in the column to the right of each part- icular trait. OESERNATIONS: CLASS SURVEY Boy . Girl Brown eye Other color Can roll tongue Cannot roll tongue Unattached earlobes Attached earlobes Widow's peak No widow's peak Hitch-hikers thumb No hitch-hikers Bent little finger No bent finger ANALXDLD AND QDNQLDDIQNS: 1. Which trait of each pair is more common? 2. Which trait of each pair do you think is dominant? Why? 68 WDNA INTROEEOTION: The common bacterium, Escherichia coli, or E. coli, is used in recombinant DNA technology. Segments of DNA can be spliced into circular forms of DNA, or plasmids. These recombinant DNA organisms then can produce proteins as the organisms grow and reproduce. W: tape scissors 1. The plasmid shown below (fig. 1) has been chemically cut at the nucleic acids indicated by dashed lines. 2. The blank segment is to be replaced by one of the follow- ing new DNA segments (fig. 2 : A, B, C). Figure 2 A 1 C 1 A B C 3. Cut out the labeled segments, then fit it into the corres- ponding plasmid following the base-pairing rule: A with T and G with C. DDDEBEAIIDN§= ANAXLDID AND QDNQLD§I9N_: 1. Explain how a mutated segment might change the intended AREENDIXD 69 70 2133:1231 LWM 1. The activities of a cell are directed by the in- formation that is carried in a. chloroplast b. ribosomes c. DNA D. mitochondria Which of the following structures is not present in an animal cell? a. cell wall b. cytoplasm c. cell membrane d. well-defined nucleus A membrane that is selectively permeable will allow what substances to pass through? a. a polar molecule b. a molecule that is insoluble in the phospholipid molecules c. a small molecule d. starch A double layer of phospholipid molecules with proteins embedded in the phospholipids would best describe the structure of the a. ribosomes b. mitochondria c. cell wall d. plasma membrane A DNA molecule resembles a twisted ladder with a. sides composed of sugar-phosphate chains b. rungs composed of nitrogen bases c. rungs held together by hydrogen bonds d. All of the above The coded messages in DNA a. produce ribosome molecules b. are controlled by transfer RNA c. are read by lysosomes d. determine amino-acid sequence in proteins 71 RNA differs from DNA in all of the following ways except a. it contains ribose instead of deoxyribose b. it consists of a single strand c. it has a phosphate component d. it contains the base uracil instead of thymine 10. 11. 12. 13. Which of the following RNA molecules carries the protein blueprint out of the nucleus to a ribosome? a. b. c. d. The a. b. c. d. mRNA tRNA tRNA all of the above cell theory states that all cells come from protein carbohydrates nucleic acid other cells Mitosis always occurs cytokinesis. a. b. c. d. before after during instead of The entire framework of microtublules assembled within a cell during prophase is called the a. b. c. d. spindle fiber mitotic spindle aster kinetochore For unicellular organisms, mitosis and cell division aid in a. b. c. d. e. growth replacement of body reproduction maintenance all of the above Mendel crossed pea plants containing green pods (yy) with plants containing yellow pods (YY). The result- ing offspring were a. b. c. d. 100 percent green 50 percent yellow 100 percent yellow 25 percent green 14. 15. 16. 17. 18. 19. 20. 72 Organisms with the genotypes 8b and BB have the same phenotype because a. B is dominant over b b. both organisms are homozygous c. the recessive trait reappeared d. both organisms are hybrids In pea plants, purple flowers are dominant over white flowers. If two heterozygous purple-flowered plants are crossed, the resulting ratio of phenotypes in the F one generation is a. 1:1 b. 2:1 c. 3:1 d. 1:2:1 If a heterozygous, short-haired black rabbit (Bst) is crossed with a long-haired brown rabbit (bbss), the percent of short-haired brown rabbits in the F one generation is a. 100 percent b. 50 percent c. 25 percent d. 0 percent Crossing over a. takes place during mitosis b. may cause linkage groups to break apart c. creates new genetic information d. both a and c Which of the following human traits are not governed by multiple genes? a. eye color b. blood type c. skin color d. height Distinct groups within a species are called a. races b. gene pools c. clones d. mutations Chemical reactions in the mitochondria a. are not important to the cell b. are energy releasing c. help digest food in the cell I. 73 POST-TEST Noltlolooluoioo 1. The activities of a cell are directed by the inform- ation that is carried in a. ribosomes b. mitochondria c. chloroplasts d. DNA 2. Which of the following structures is not present in an animal cell? a. well-defined nucleus b. cell wall c. cell membrane d. cytoplasm 3. A membrane is selectively permeable will allow what 4. S. substances to pass through? a. starch b. a small molecule c. a polar cell d. a molecule that is insoluble in the phospholipid molecules A double layer of phospholipid molecules with proteins embedded in the phospholipids would best describe the structure of the a. plasma membrane b. mitochondria c. ribosomes d. cell wall A DNA resembles a twisted ladder with a. rungs held together by hydrogen bonds b. sides composed of sugar-phosphate chains c. rungs composed of nitrogen bases d. all of the above The coded messages in DNA a. are controlled by transfer RNA b. are read by lysosomes c. determine amino-acid sequence in proteins d. produce ribose molecules 10. 11. 12. 13. 74 RNA differs from DNA in all of the following ways ex- cept a. it has a phosphate component b. it contains the base uracil instead of thymine c. it consist of a single strand d. it contains ribose instead of deoxyribose Which of the following RNA molecules carries the protein blueprint out of the nucleus to a ribosome? a. rRNA b. mRNA c. tRNA d. all of the above The cell theory states that all cells come from a. nucleic acid b. protein c. other cells d. carbohydrates Mitosis always occurs cytokinesis. a. during b. instead of c. before d. after The entire framework of microtubules assembled within a cell during prophase is called the a. aster b. spindle fiber c. mitotic spindle d. kinetochore For unicellular organisms, mitosis and cell division aid in ,a. replacement of body parts b. maintenance ' c. growth d. reproduction e. all of the above Mendel crossed pea plants containing green pods (yy) with plants containing yellow pods (YY). The result- ing offspring were a. 25 percent green b. 100 percent green c. 50 percent yellow d. 100 percent yellow 14. 15. 16. 17. 18. _19. a. b. C. d. 20. 75 Organisms with the genotypes 8b and BB have the same phenotype because a. both organisms are hybrids b. B is dominant over b c. the recessive trait reappeared d. both organisms are homozygous In pea plants, purple flowers are dominant over white flowers. If two heterozygous purple-flowered plants are crossed, the resulting ratio of phenotypes in the F one generation is a. 3:1 b. 1:2:1 c. 1:1 d. 2:1 If a heterozygous, short-haired black rabbit (Bst) is crossed with a long-haired brown rabbit (bbss), the percent of short-haired brown rabbits in the F one generation is a. 0 percent b. 25 percent c. 50 percent d. 100 percent Crossing over a. may cause linkage groups to break apart b. takes place during mitosis c. creates new genetic information d. both a and c Which of the following human traits are not governed by multiple genes? a. skin color b. height c. eye color d. blood type Distinct groups within a species are called phenotypes races clones gene pools Chemical reactions in the mitochondria a. are energy releasing b. help digest food in the cell c. are not important to the cell 76 77 EYALDAIIQN EDEN RATING SCALE: STRONGLY AGREE 5 AGREE SOMEWHAT 4 10. NEITHER AGREE NOR DISAGREE DISAGREE SOMEWHAT STRONGLY DISAGREE HNM This unit improved my understanding of cell biology. Laboratory activities were enjoyable and use- ful. The directions for activities were clear and simple to follow. The labs presented were easily comprehended. This program challenged my interest to learn. I would highly recommend this unit to be used by other biology students. I prefer this method of learning to others. There was enough time to complete each of the activities. ‘ This program helped to improve my attendance. I looked forward to doing the laboratory act- ivities. 78 79 DIDLIQQBAENX Baver, P.H., et al. 1985 LAEQTQEOEy mggggI for eEperi- DEDDé in EIOIOgy. 2nd ed. Laidlaw Brothers, River Forest, Illinois. Bybee, R.W., C.E. Buchwald, S. Crissman, et al. 1989. Science and technology education for the elementary years: Frameworks for curriculum and instruction. Andover, MA: The National Center for improving Science Education. Hummer, P.J., et al. 1983 RTQEiAg leveI§ QT 11:21 A lAE- QIQLQEX Eggual. Charles E. Merril Publishing Company, Columbus, Ohio. Kaskel A., et al. 1979. LALQTAEQLX Eiglggy, C.E. Merril Publishing Co., Columbus, Ohio. McLaren, J.E., et al. 1991 NDADD bioIggy, D.C. Heath and Company, Lexington, Massachusetts. Thompson, R., et al. 1991 Reagn EIQIng laboratory in- vestigations. D.C. Heath and Company, Lexington, Mass- achusetts. Uno, G.E., 1990. Inquiry in the classroom. BioScience 40: B 41-43. Yeany, R. 1990. Response to Von Glasersfeld. Paper pre- sented at the general session of the meeting of the Nat- ional Association for Research in Science Teaching, Atlanta, Georgia.