Title Page

Genetics Unit plan DNA Structure and Replication

Douglas S Johnson

Grades 10 11 and 12

Duration: 9 days / 4 Block Schedule

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Table of Contents

Purpose of the unit p 3

Academic Standards p 3

Objectives p 3-4

Interdisciplinary connections p 4

Assessments p 4

Vocabulary p 5

Timeline p 6

Resources p 6-7

Technology p 7

Lesson Plans p 8-13

Differentiation p 13

Critical Thinking Skills p 13

Pre test p 14-18

Post Test p 19-24

Graphs p 24-26

Narrative Statements p 27-30

Rubric Separate file

Power Points Used Separate file

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Purpose of the unitThe purpose of this unit is to help students gain a more advanced understanding of DNA structure, the process of replication, and mutation. Because this is a Genetics course there are no standards directly associated with it. I have utilized some of the life science standards to help connect the topics discussed with important biological concepts. The primary areas I will focus on during this unit include an advanced understanding of the chemical structure of DNA, the importance of histones in DNA structure, the process of replication, errors that can occur during replication, and historical figures and experiments that were important in the understanding of DNA structure and replication. To teach this unit I will utilize several different types of instruction including; power points, developing a timeline, developing concept maps, a DNA extraction lab, and a project that involves presenting a concept involved in the chapter to the rest of the class.

Standards

B.1.23 Understand that and describe how inserting, deleting, or substituting DNA segments can alter a gene. Recognize that an altered gene may be passed on to every cell that develops from it, and that the resulting features may help, harm, or have little or no effect on the offspring’s success in its environment.

B.1.24 Explain that gene mutations can be caused by such things as radiation and chemicals. Understand that when they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only.

B.1.26 Demonstrate how the genetic information in DNA molecules provides instructions for assembling protein molecules and that this is virtually the same mechanism for all life forms.

B.1.27 Explain that the similarity of human DNA sequences and the resulting similarity in cell chemistry and anatomy identify human beings as a unique species, different from all others. Likewise, understand that every other species has its own characteristic DNA sequence.

Objectives

Students will understand the following-DNA is the molecule of heredity and protein synthesis-DNA is composed of 4 bases adenine is complimentary to thiamine and guanine is complementary to cytosine.

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-DNA is a double helix composed of complimentary strands, which replicate semiconservatively.-DNA sequences can be altered by mutation, which alters the proteins made. -Every organism has its own protein sequence.

Essential Questions

-What are the two primary purposes of DNA?-What would DNA have to do to fulfill these purposes?-What is a mutation, and how would it affect the DNA sequence?-How could mutations be beneficial?-How do we know the function, and structure of DNA?-Could any other structure serve the same function as DNA?-Why are enzymes needed for DNA to function properly?

Interdisciplinary connections

History-Discuss the historical figures involved in discovering DNA structure and replication understandings- students develop a timeline. Speech- Students develop power points and present them to the class. Chemistry- Students are taught the chemical structures involved in DNA and the way the chemicals interact during DNA function and replication. Mathematics-Discuss the reasons mathematically 4 bases can be translated into 20 amino acids using a triplet code. .

Assessment Evaluation

Concept Map 10 ptsAssessment Questions 10 ptsDiscussion 10 pts Lab 10 ptsPre-test 10 ptsPost-test 50 ptsPresentation 25 pts Extra Credit 10 ptsTotal 125 Pts

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Vocabulary Ribose- Five carbon sugar included in RNA backbone C5 H10 O5Deoxyribose-Five carbon sugar included in DNA backbone C5 H10 O4Purine- Two ring nitrogen bases include Guanine and AdeninePyrimidines- One ring nitrogen bases include Cytosine and ThymineNucleotide- One unit of a DNA molecule includes 1 Phosphate, 1 Deoxyribose sugar, and one base.Histone-Proteins that function in DNA packing and functionNucleosome-a group of 8 histones that function as a single unitChromatin- DNA and histones in an unwound form, is able to function in RNA synthesis.Chromosome- DNA and Histones that are packed to be able to be separated during replication, RNA can not be synthesized while DNA is in this formSemiconservative Replication- DNA splits and each strand forms a new DNA unitReplication Fork-The site where DNA is locally opened for replication to occur Toipomerase-Enzyme that relieves stress on DNA during unwindingHelicase-Enzyme that separates DNA strandsDNA polymerase- Enzyme that adds basses to unwound DNA strands (only works in a 3-5 direction.RNA primer- Creates places for DNA polymerase to bond to on the lagging strandLigase- Enzyme that joins Okazaki fragments togetherOkazaki fragments- The lagging strand is copied in pieces due to the DNA polymerase only reading in one directionLeading strand- The DNA strand that has a free 3’ endLagging strand- The DNA strand that does not have a free 3’ end

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Timeline

Day 1 Pre-Test Lecture on DNA Structure Video Picture 51Homework: Read 9.1-9.2Review questions 1-6

Day 2 Lab DNA extractionDay 3 Lecture Personalities involved in DNA discoveries

Online Discussion Who was the most important person involved in the understanding of DNA?Students must reply to two other posts.Homework Read 9.3Answer Discussion Questions 7-16

Day 4 Lecture DNA replication and mutations Students must draw the replication fork with all enzymes involved Make a concept map of chapter www.bubbl.com Video DNA replication http://highered.mcgraw-hill.com/sites/0073525278/http://highered.mcgraw-hill.com/sites/0073525278/

Day 5 Review discussion questions Review previous lecturesCritical Thinking Questions in class Practice test Complete Study Guide

Day 6 Post test DNA structure and replicationWork on Presentations

Day 7 Work on presentationsDay 8 Presentations Day 1Day 9 Presentations day 2

Resources Lewis, R. 2010. Human Genetics Concepts and Applications ninth addition. McGraw-Hill. New York, NY.

Klug, W.S. 2009. Concepts of Genetics 9th addition. Pearson Education. Inc., San Francisco, CA.

Miller, K., Levine, J. 2005. Biology. Pearson Education. Inc., Upper Saddle River, NJ.

DNA necklace Lab, Carolina Biological Supply Company. Burlington, NC.

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Web sites www.bubbl.comhttp://highered.mcgraw-hill.com/sites/0073525278/http://highered.mcgraw-hill.com/sites/0073525278/

Technology

Power Points- I use 3 power point presentations as a way to present materials to the students in a way that is interesting and visually stimulating. Students develop their own power points to present to their classmates. Moodle- I use Moodle an online database and testing center for this lesson, for a discussion board, to administer pre and post tests, to display helpful resources and links, and as a place for the students to turn in completed work.DNA extraction-This lab was purchased through Carolina, and included materials for students to extract and separate DNA from their cheek cells.Concept Map-The students use www.bubbl.com to develop a concept map of the chapter.Video on line –I use a few short online videos about DNA structure and replication that the students are able to access from Moodle.

Lesson Plans

#1 DNA Structure (2 days)

OverviewIn this lesson students will learn about the chemical composition of DNA. These students have already been exposed to the basic nature of DNA in Freshman Biology, this class will go into much greater detail into the chemicals involved and how they interact with each other. This lesson involves a day of lecture and text exploration as well as a lab in which the students are able to extract and physically see their own DNA.

Standards-B.1.26 Demonstrate how the genetic information in DNA molecules provides

instructions for assembling protein molecules and that this is virtually the same mechanism for all life forms.

B.1.27 Explain that the similarity of human DNA sequences and the resulting similarity in cell chemistry and anatomy identify human beings as a unique species, different from all others. Likewise, understand that every other species has its own characteristic DNA sequence.

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ObjectivesStudents will understand the following -DNA is the molecule of heredity and protein synthesis-DNA is composed of 4 bases adenine is complimentary to thiamine and guanine is complementary to cytosine.-DNA is a double helix composed of complimentary strands

Procedures

EngageBegin the lesson by asking the students what they know about the structure and purpose of DNA. Use what they already know to begin to build a more specific understanding of DNA’s chemical content. For example the students may know that DNA has a sugar phosphate backbone, but probably will not know that the sugar has 5 carbons, that are labeled in a specific order, and the phosphates are connected by phosphodiester bonds to the 3 and 5 prime carbons. During day 1 we will discuss this structure as well as its relation to histone proteins using a power point. On day two of the lesson will begin by asking what DNA looks like, then asking if the students think they can extract their own DNA easily. ExploreThe primary exploration in this lesson will occur during the DNA necklace lab (day 2). During this lab students will swab their cheek cells, add soap, and then ethyl alcohol. The DNA will condense out from the alcohol into a stringy looking substance. Explanation/ ElaborationAfter the lab the students will answer questions that combine concepts from the lecture with the procedures in the lab. For example what is the chemical component in DNA that allows it to not dissolve in the alcohol.

Assessment/Evaluation Formal- The Laboratory will be graded Informal- during the lecture I will ask each student specific questions to gauge understanding.

MaterialsPower Point- DNA structureLab- DNA Necklace Kit (Carolina)Power Point DNA Structure

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#2 Historical figures (1 day)

OverviewIn this lesson students will explore the key historical figures involved in the current understanding of DNA structure and the experiments they used to gain this understanding. This is a one day lesson that involves a power point lecture about the historical figures and their experiments After the lecture students develop a timeline of these figures. Standards-B.1.24 Explain that gene mutations can be caused by such things as radiation and

chemicals. Understand that when they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only.

B.1.26 Demonstrate how the genetic information in DNA molecules provides instructions for assembling protein molecules and that this is virtually the same mechanism for all life forms.

Objectives-DNA is the molecule of heredity and protein synthesis-DNA is composed of 4 bases adenine is complimentary to thiamine and guanine is complementary to cytosine.-DNA is a double helix composed of complimentary strands, which replicate semiconservatively.

ProceduresEngageBegin the class by asking questions such as; how long have we understood the importance of DNA? How do we know DNA is the hereditary material? What historical figures do you already know? Then discuss that for a long time the majority of humanity believed that protein was the hereditary material, because their was only 4 bases, but 20 amino acids. It made much more sense that the amount of variation that exist is from the 20 Amino acids, until we realized how those bases coded for proteins.

ExploreThe students will continue to explore the contributions of different personalities using both their textbooks, and online resources. The students are required to develop a timeline using at minimum the persons discussed in class, and also at least two others. The students have the option to use a power point, a word document, or make the timeline by hand.

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Explanation/ ElaborationOn Moodle the students are required to complete a discussion board answering the question; who is the most important historical figure involved in DNA discovery, and why? The students need to write one journal entry, and respond to two others.

Assessment/Evaluation Formal- Timeline Formal- Discussion BoardInformal- Asking engaging questions to each student during the lecture

Materials Power Point- Historical Figures Moodle- Journal entryPower Point Historical Figures

#3 Replication and Mutation (1 day)

OverviewIn this lesson students will learn about DNA replication and Mutation. The students will have to be able to draw the DNA fork, including the primary enzymes involved and their functions. The students will also learn more detail about possible mutations that can occur during DNA replication. This lesson will conclude with the students bringing all the materials discussed in this unit together by using an online concept map. Standards-B.1.23 Understand that and describe how inserting, deleting, or substituting DNA

segments can alter a gene. Recognize that an altered gene may be passed on to every cell that develops from it, and that the resulting features may help, harm, or have little or no effect on the offspring’s success in its environment.

B.1.24 Explain that gene mutations can be caused by such things as radiation and chemicals. Understand that when they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only.

ObjectivesStudents will understand -DNA sequences can be altered by mutation, which alters the proteins made. -Every organism has its own protein sequence.-The DNA replication fork and the primary enzymes associated with it

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ProceduresEngageBegin the class by asking the students why variation exists in life. Several students may say it is because different traits exist or different genes exist in nature. Then ask what causes these differences. The ultimate answer being sought is mutations. Then lead the discussion toward replication. When during the cell cycle does replication take place? How often does replication take place? How does replication take place?ExploreDuring the power point lecture we will focus on the enzymes involved in replication, the replication fork, the proof for semi-conservative replication, and the type of mutations that can occur. After we finish discussing each topic I will show a short video to further develop the student’s knowledge of the topic. The students are also expected to read about the topic in their textbooks.ExplanationThe students are expected to be able to draw the replication fork and label the following enzymes; toipomerase, helicase, DNA polymerase, DNA ligase, and DNA primers. The students are also expected to label the direction that DNA polymerase is able to read and copy DNA strands, and the method of copying the lagging strands of DNA (Okazaki fragments).ElaborationAfter the lesson is complete the students will make a concept map of the entire unit using an online concept map program www.bubbl.com. This program uses bubbles linked by lines representing specific relationships. Assessment/Evaluation Formal- Replication Forks and Concept Maps

ResourcesPower Point DNA replication and MutationWeb site www.bubbl.comOnline tutorials http://highered.mcgraw-hill.com/sites/0073525278/http://highered.mcgraw-hill.com/sites/0073525278/

#4 Presentations (4 days)

OverviewIn this section of the unit students will develop power points using a subject that is directly related to the unit. Then each student will present his or her power point to the class. The students will be graded based on a RUBRIC, which uses specific grading criteria. The criteria include; time limit, accuracy, aesthetics of the power point, presentation skills, and peer evaluations. The students are able to choose their topics based on their interests, but I will approve these topics, based on topics

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I believe the students have the opportunity to present successfully. The students will use these same criteria to grade each other. StandardsB.1.23 Understand that and describe how inserting, deleting, or substituting DNA

segments can alter a gene. Recognize that an altered gene may be passed on to every cell that develops from it, and that the resulting features may help, harm, or have little or no effect on the offspring’s success in its environment.

B.1.24 Explain that gene mutations can be caused by such things as radiation and chemicals. Understand that when they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only.

B.1.26 Demonstrate how the genetic information in DNA molecules provides instructions for assembling protein molecules and that this is virtually the same mechanism for all life forms.

B.1.27 Explain that the similarity of human DNA sequences and the resulting similarity in cell chemistry and anatomy identify human beings as a unique species, different from all others. Likewise, understand that every other species has its own characteristic DNA sequence.

ProceduresEngageI will begin this class by presenting the Rubric and requirements for the assignment, and then discuss a range of possible topics. These topics can be fairly broad in that any specific mutation is in play. Some possible topics could include; cystic fibrosis, Huntington’s disease, different types of mutations, a specific historical figure, X-ray technology ands its place in the discovery of DNA structure, Histone proteins, and many more. ExploreStudents will immediately start to research their topics. They need to have chosen their topics by the end of the first day. I will try to push more advanced students toward more difficult topics, and less advanced students toward less challenging topics. I will also try to get students to choose topics they may have familiarity with. The students will have another full day of class to develop their power points. Explanation/ElaborationThe students will have 10-15 minutes to discuss their topics. They will be graded based on the categories included in the Rubric. The students will also grade their peers, based on the same categories. Although grades will not be determined based on these evaluations, the students will be graded based on putting effort into grading their peers. I hope this will help students pay attention to the presentations, begin to think critically about presentation skills, and get more

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feedback about things they can do to improve presentation skills in the future. I will not give students the actual peer evaluations, but I will give them helpful comments from their peers. Assessment/Evaluation Formal-Rubric for presentations Informal- Peer evaluations

ResourcesPresentation Guide Rubric

Differentiation There are several areas I use differentiation in this lesson. Primarily I allow a wide range of interpretation in the way specific assignments can be accomplished. When completing the journal articles and timelines the students have a wide variety of interests they can follow. If there is a person they connect to they can develop that connection, if there is someone that does not interest them they can give them limited attention, or none at all. The concept map works similarly, the areas that the students’ feel most comfortable they can develop the most. More advanced students have the opportunity to develop these ideas as far as they want, the less advanced students can use simpler ideas without penalty. The next way I use differentiation is with the extra credit assignments. For extra credit the students have the choice of either making posters dealing with ideas from the unit, or summarizing journal articles dealing with concepts involved in the unit. Students who are artistic can make posters, those who enjoy reading and writing can take advantage of the article summaries. The primary differentiation in this unit involves the presentations. There is a wide variety of topics the students are able to choose from, and there are many topics that can be explored at multiple levels. I think one of the best ways the presentations can be differentiated is based on personal experience. Humanities differences are based on different genetic mutations; therefore each of us has our own mutations we can explore.

Critical Thinking SkillsIn this unit plan I try to give students many opportunities to develop multiple critical thinking skills. Some of the skills I try to incorporate include; organization, communication, interpretation, and reasoning skills. The concept maps and timelines both are focused on developing organizational skills. Both of these exercises will hopefully provide many of the students with new resources they can continue to utilize in their education careers. Communication is developed during the presentations, in which the students are not only to utilize speaking skills, but to also use nonverbal skills, and their ability to evaluate others. To develop their power points and timelines they will use online resources, I will help the students find resources that challenge their interpretive abilities. With a stronger vocabulary involving DNA structure and replication they are able to interpret more challenging

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sources. During lectures I will continually ask challenging questions. These questions will involve using information that the students came in to class with or are provided during the lecture; to reasonably induce or deduce the answers. The test also includes questions that require different levels of reasoning skills to answer.

Pre-test

Question 1Kary Mullis invented _____, which uses DNA replication to mass-produce selected DNA sequences in the laboratory.

a. DNA structure

b. Okazaki fragments

c. the polymerase chain reaction

d. nucleosomes

Question 2 In the Meselson and Stahl experiment, the second generation daughter molecules contained ____ DNA molecules, which was consistent with semiconservative DNA replication.

a. LL and HH

b. LL and LH

c. LL , HH, and LH

d. LH and HH

Question 3 Identification of DNA as a helical molecule was first shown in 1952 by _____.

a. Chargaff

b. Hershey and Chase

c. Watson and Crick

d. Franklin

Question 4 Griffith identified a substance capable of transmitting infectiousness, which ____ later showed was DNA.

a. Hershey and Chase

b. Garrod

c. Watson and Crick

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d. Avery, MacLeod, and McCarty

Question 5 The current model of DNA structure was proposed by _____.

a. Chargaff

b. Avery

c. Griffith

d. Watson and Crick Question 6 A ____ is a DNA base with a single-ring structure, for example, cytosine and thymine.

a. purine

b. nucleotide

c. pyrimidine

d. sugar-phosphate backbone

Question 7 The enzyme primase is required for DNA replication because ______.

a. the enzyme binds small pieces of DNA together

b. primase breaks the hydrogen bonds holding the two strands together

c. DNA polymerase can only add bases to an existing nucleic acid strand

d. the primase corrects any errors made by the DNA polymerase

Question 8 Considering DNA replication along the template strand, what event takes place first?

a. DNA polymerase begins adding DNA nucleotides.

b. Primase removes the 5' phosphate.

c. Primase adds an RNA primer.

d. DNA polymerase begins adding RNA nucleotides.

Question 9 If Hershey and Chase had found S35 rather than P32 in progeny phages, their experiment would have demonstrated that _____.

a. phage protein enters the host cell

b. phage DNA enters the host cell

c. proteins contain phosphorus

d. DNA contains sulfur

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Question 10 If a DNA molecule contains 20% A, approximately what percentage of G is present?

a. 40%

b. 20%

c. 30%

d. 60%

Question 11 The two strands in a DNA molecule are _____.

a. identical

b. complementary

c. antiparallel

d. Two of these answers are correct

.Question 12 ____ DNA synthesis produces Okazaki fragments on one strand of the DNA template.

a. Continuous

b. Conservative

c. Discontinuous

d. Dispersive

Question 13 Which of the following is not a component of chromatin?

a. DNA polymerase

b. histone proteins c. DNA binding proteins

d. RNA

Question 14 DNA nucleotides pair via hydrogen bonds. The base thymine forms a complementary base pair with _____.

a. guanine

b. thymine

c. cytosine

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d. adenine

Question 15 If DNA polymerase could add bases in the 3' to 5' direction, there would be no need for _____.

a. Okazaki fragments

b. PCR

c. helicase

d. DNA ligase

Question 16 Which strand below would be the sequence 3' AAACGCTT 5' complimentary strand?

a. 5' AAGCGTTT 3'

b. 5' GGGTATCC 3'

c. 5' AAACGCTT 3'

d. 5' TTTGCGAA 3'

Question 17 ____ unwinds and opens up the DNA helix during replication

a. Primase

b. Ligase

c. Helicase

d. DNA polymerase

Question 18 The first group of researchers to demonstrate that proteins are not the hereditary material were _____.

a. Hershey and Chase

b. Franklin and Pauling

c. Watson and Crick

d. Garrod and Miescher .Question 19 Energy is required to break the hydrogen bonds holding the bases together. Which pair will be the most difficult to separate?

a. C - G

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b. A - C

c. G - T

d. A - T

Question 20 Who was the first to discover than inborn errors of metabolism are due to enzymes?

a. Watson and Crick

b. Franklin

c. Griffith

d. Garrod

Question 21 Enzymes called ____ catalyze the formation of covalent bonds that hold together the sugar-phosphate backbone of the DNA molecule..

a. primases

b. RNA polymerases

c. ligases

d. helicases

Question 22 If a nucleic acid is found to contain 20% A and 20% T, the molecule is probably _____.

a. double-stranded DNA

b. double-stranded RNA

c. single-stranded DNA

d. single-stranded RNA

Question 23 ______ are the building blocks of DNA.

a. Nucleotides

b. Histones

c. Proteins

d. Phosphates

Question 24 DNA replication is _____.

a. conservative

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b. dispersive

c. semiconservative

d. semidispersive

Question 25 Replication proceeds in a ____ to ____ direction.

a. 3'; 3'

b. 3'; 5'

c. 5'; 3'

d. 5'; 5'

Post Test

Question1 Frederick Griffith was a microbiologist who observed that:

a. nonvirulent bacteria become virulent when mixed with heat-killed virulent bacteria.

b. DNA contains nitrogen and phosphorus.

c. RNA from heat-killed bacteria transforms nonvirulent bacteria.

d. bacteria, proteases disrupt transformation from nonvirulence to virulence.

Question 2 If the sequence of one strand of a DNA molecule is 5' ATGGCAT 3', the sequence of the complementary strand is:

a. 3' ATGGCAT 5'.

b. 5' TACCGTA 3'.

c. 3' TACCGTA 5'.

d. 5' ATGGCAT 3'.

Question 3 DNA entwined around an octet of proteins is called a:

a. karyosome.

b. nucleosome.

c. ribosome.

d. nucleotide.

Question 4 DNA strands are antiparallel, so replication proceeds:

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a. continuously on both strands for a time, and then discontinuously.

b. continuously on both strands.

c. continuously on one strand and discontinuously on the other.

d. discontinuously on both strands.

Question 5 Watson and Crick based their conclusion that DNA is a double helix on results ofphysical experiments performed by:

a. Avery, MacLeod and McCarty.

b. Mendel and Darwin.

c. Chargaff, Wilkins and Franklin.

d. Hershey and Chase.

Question 6 In experiments to show that DNA is the genetic material, Hershey and Chase labeledDNA with radioactive:

a. amino acids.

b. sulfur.

c. carbon.

d. phosphorus.

Question 7 If DNA is compared to a spiral staircase, then steps of the staircase would correspond to:

a. base pairs.

b. hydrogen bonds.

c. nucleotides.

d. sugars.

Question 8 This enzyme creates phosphodiester bonds between Okazaki fragments.Choose one answer.

a. Ligase

b. Helacase

c. DNA polymerase.

d. Topoisomerase.

Question 9 DNA replication is:

a. dispersive.

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b. semi-conservative

c. discontinuous on both strands.

d. conservative.

Question 10 Hershey and Chase demonstrated that DNA was the genetic material using:

a. viruses and a blender.

b. frogs and a dishwasher.

c. humans.

d. mice and a blender.

Question 11 If a strand of DNA has 40% Guanine how much adenine will it have?

a. 40%

b. 60%

c. 20%

d. 10%

Question 12 In eukaryotic chromosomes, replication starts at:

a. multiple sites along the length of the chromosome.

b. a single origin of replication.

c. one replication fork on each chromosome.

d. a nucleosome.

Question 13 Okazaki fragments are small pieces of:

a. RNA

b. Protein

c. Enzymes

d. DNA

Question 14 This enzyme pulls the strands of DNA apart.

a. Helicase.

b. Topoisomerase.

c. Ligase.

d. RNA polymerase.

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Question 15 ______ first noted an acidic substance in the nuclei of cells from pus.Choose one answer.

a. Watson

b. Mendel

c. Miescher

d. McCarty

Question 16 In humans, DNA in the nucleus winds around proteins called:

a. karyosomes.

b. histones.

c. ribosomes.

d. histiosomes.

Question 17 Which substance is not part of DNA?

a. phosphate

b. ribose

c. nitrogen

d. cytosine

Question 18 Which researchers showed that DNA is the genetic material?

a. Watson and Crick

b. Hershey and Chase

c. Garrod and Griffith

d. Meselson and Stahl

Question 19 In DNA, cytosine binds with:

a. thymine.

b. adenine.

c. guanine.

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d. uracil.

Question 20 The sugar-phosphate backbone of DNA is held together by:

a. disulfide bridges.

b. phosphodiester linkages.

c. phosphate bonds.

d. hydrogen bonds.

Question 21 The nitrogenous bases adenine and thymine are:

a. both purines.

b. both pyrimidines.

c. a pyrimidine and a purine, respectively.

d. a purine and a pyrimidine, respectively.

Question 22 In a molecule of DNA, purine bases form ______ bonds with pyrimidine bases.

a. phosphate

b. phosphodiester

c. hydrogen

d. disulfide

Question 23 Meselson and Stahl performed experiments to show that DNA replication is:

a. antiparallel.

b. dispersive.

c. semi-conservative.

d. discontinuous.

Question 24 In DNA which carbon atom on the deoxyribose sugar is the base attached to?

a. 5

b. 1

c. 2

d. 3

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Question 25 The enzyme that inserts the correct bases in a growing nucleotide chain in a replicatingDNA molecule is:

a. Ligase.

b. DNA polymerase.

c. RNA polymerase.

d. Topoisomerase.

Charts

Pretest

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Post-test

Pretest verses Post-test

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Presentation Bar graph

Narrative Statements

Unit Narrative Standards usedB.1.23 Understand that and describe how inserting, deleting, or substituting DNA

segments can alter a gene. Recognize that an altered gene may be passed on to every cell that develops from it, and that the resulting features may help, harm, or have little or no effect on the offspring’s success in its environment.

B.1.24 Explain that gene mutations can be caused by such things as radiation and chemicals. Understand that when they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to descendant cells only.

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B.1.26 Demonstrate how the genetic information in DNA molecules provides instructions for assembling protein molecules and that this is virtually the same mechanism for all life forms.

B.1.27 Explain that the similarity of human DNA sequences and the resulting similarity in cell chemistry and anatomy identify human beings as a unique species, different from all others. Likewise, understand that every other species has its own characteristic DNA sequence

Students of different abilitiesIn this class I had a wide range of students with different abilities and learning types. I had two students who were below average, four students who were very good students, and one student with Aspergers. In order to accommodate this wide variety in learning styles I utilized a wide variety of individualized learning opportunities. When completing the journal articles and timelines the students had a wide variety of interests they could follow. If there is a person they connect to they could develop that connection. The concept map worked similarly, the areas that the students’ felt most comfortable with they could develop the most. For more advanced students they had the opportunity to develop these ideas as far as they wanted, the less advanced students could use simpler ideas without penalty. For extra credit the students had the choice of either making posters dealing with ideas from the unit, or summarizing journal articles dealing with concepts involved in the unit. Students who are artistic could make posters, those who enjoyed reading and writing could take advantage of the article summaries. Different students in this class took advantage of each of these opportunities. The primary differentiation in this unit involved the presentations. There was a wide variety of topics the students were able to choose from, and there were many topics that could be explored at multiple levels. I think one of the best ways the presentations were differentiated was based on personal experience. There was a student who had color blindness in his family that discussed color blindness. A student that had a grandmother with Alzheimer’s discussed that topic. The individual with Aspergers was able to discuss the genetic components of his disorder.

Critical ThinkingIn this unit plan I tried to give students many opportunities to develop multiple critical thinking skills. Some of the skills used include; organization, communication, interpretation, and reasoning skills. The concept maps and timelines both were focused on developing organizational skills. Both of these exercises provided many of the students with new resources they can continue to utilize in their education careers. Communication was developed during the presentations, in which the students not only to utilized speaking skills, but also used nonverbal skills, and their ability to evaluate others. To develop their power points and timelines they were able to use online resources, I helped the students find resources that challenged their interpretive abilities. With a stronger vocabulary involving DNA structure and replication they were able to interpret more challenging sources. During lectures I continually asked challenging

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questions. These questions involved using information that the students came in to class with or I provided during the lecture. The test also included questions that require different levels of reasoning skills to answer.

Instructional Strategies-Power Point lectures- Online discussions -Concept Maps –Laboratory exercises-Videos-Reading-Answering Chapter Questions -Researching-Assessing prior knowledge -Drawing -Note taking -Study guide-Testing-Presenting

TechnologyPower Points- I used 3 power point presentations as a way to present materials to the students in a way that was interesting and visually stimulating. Students developed their own power points to present to their classmates. Moodle- I used Moodle an online database and testing center for this lesson, for a discussion board, to administer pre and post-tests, to display helpful resources and links, and as a place for the students to turn in completed work.DNA extraction-This lab was purchased through Carolina, and included materials for students to extract and separate DNA from their cheek cells.Concept Map-The students used www.bubbl.com to develop a concept map of the chapter.Video on line –I used a few short online videos about DNA structure and replication that the students were able to access from Moodle.

Assessment Narratives There was no accommodations needed for students for assessment

Project Narratives DirectionsWhen presenting the project, I first explained what the project was about. They would be presenting 10 to 15 minutes on a topic related to the materials covered in the unit using a power point. I then discussed possible topics they could use, and suggested picking a topic they may have had some personal experience with. I told they class that all topics had to be cleared by me, and if they were having trouble

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picking one I could help them. Finally I presented the Rubric and discussed line by line the requirements for each category. Then I made sure they understood that they needed to rate their peers, and discussed what they would be looking for when watching other presentations.

Standards This project was directly related to each standard in that the students had to be able to understand key information in the standard to successfully be able to discuss their topics.

Accounting for differences This project was designed to account for differences in experiences, interests, and academic abilities. The primary way this was done was by guiding students toward particular topics, while allowing them choices in this selection. I also tried to work with each student during the research and design processes to help them develop presentations they were able to understand well enough to successfully present it. My favorite part about this project was when students choose topics they had experience with; for example one student with Aspergers presented about the genetic components of this disorder.

Real Life ApplicationsIn the real world in order to be successful a person almost always has to be competent in public speaking, research techniques, critical thinking skills, and evaluation. This project was able to address each of these. Many of the students had not had a large amount of public speaking opportunities; the more they can get the more capable they will become.

Project Rubric / Criteria for the projectThe criteria included; time limit, accuracy, aesthetics of the power point, presentation skills, and peer evaluations. When I was initially presenting the project we discussed each individual criteria and what they would have to do to get specific scores for each. A Rubric was used to present and grade these criteria.

Evaluation of student learning Narratives

Pretest The average score on the pretest was 15 out of 50, the average score based on guessing would have been about 12.5 out of 50. There did not seem to be any consistency about which questions were missed more often then others. The high score on the pretest was 24 out of 50. The overall class prior understanding of this unit was minimal.

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Changes Based on PretestAfter the pretest I determined that the prior knowledge for the unit was minimal, and I would need to take time during the lectures to review basic principles involved in DNA structure before I began to teach the more complicated theories.

ProjectThe students did a very good job on the project. The average score was 46 out of 50. Every student got their maximum score on Power Point organization and time limit. I was impressed with how well prepared every student was. The area that the students struggled with the most was presentation skills. It was difficult for many of them to make eye contact with the audience and to not read too much directly off the Power Point. I expected this from students who had not had a large amount of practice public speaking.

Post-testThe Post-test scores ranged from 13 to 44 out of 50. The average post-test score was 38 out of 50. Every student increased their scores, 8 out of 10 students increased their scores significantly. Two students who have also struggled on other units scored poorly on both tests. The average increase in score among the 8 students who had a significant increase in scores was 20 points, which is a 40% increase in score.

Strengths and Weaknesses of instructional approaches I thought this unit plan worked well, and the standards and topics involved were sufficiently covered using multiple teaching strategies. I feel comfortable with the lectures I utilized during the unit. The one lecture I would like to add to is the historical figures. I would like to include more interesting facts about the persons covered. Although the final test scores were better then the pretests there is a large amount of room for improvement. In the lab I would like to start with an example extraction of strawberry DNA. This is a very effective demonstration because there is a large amount of DNA in strawberries, and it is easier to see then the cheek cell DNA. I also need to find ways to more effectively include the struggling students. One of the primary reason these students scores were so low on the post-test is that the test was administered the day before spring break, and these students did not come to school that day, which means they did not take the exam until after spring break. By the time they got back to class they had forgotten most of the information they learned. I predict their scores would have still been around 25 out of 50 if they took the test before spring break. I think it may be helpful in the future to utilize more informal assessment, to keep these students caught up throughout the unit.

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