1
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
p3
Academic Standards
p3
Objectives
p 3-4
Interdisciplinary connections
p4
Assessments
p4
Vocabulary
p5
Timeline
p6
Resources
p 6-7
Technology
p7
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 unit
The 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.
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.
B.1.27
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
Assessment Questions
Discussion
Lab
Pre-test
Post-test
Presentation
Extra Credit
Total
10 pts
10 pts
10 pts
10 pts
10 pts
50 pts
25 pts
10 pts
125 Pts
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Vocabulary
Ribose- Five carbon sugar included in RNA backbone C5 H10 O5
Deoxyribose-Five carbon sugar included in DNA backbone C5 H10 O4
Purine- Two ring nitrogen bases include Guanine and Adenine
Pyrimidines- One ring nitrogen bases include Cytosine and Thymine
Nucleotide- One unit of a DNA molecule includes 1 Phosphate, 1 Deoxyribose sugar,
and one base.
Histone-Proteins that function in DNA packing and function
Nucleosome-a group of 8 histones that function as a single unit
Chromatin- 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 form
Semiconservative Replication- DNA splits and each strand forms a new DNA unit
Replication Fork-The site where DNA is locally opened for replication to occur
Toipomerase-Enzyme that relieves stress on DNA during unwinding
Helicase-Enzyme that separates DNA strands
DNA 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 strand
Ligase- Enzyme that joins Okazaki fragments together
Okazaki fragments- The lagging strand is copied in pieces due to the DNA
polymerase only reading in one direction
Leading strand- The DNA strand that has a free 3’ end
Lagging strand- The DNA strand that does not have a free 3’ end
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Timeline
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
Day 8
Day 9
Pre-Test
Lecture on DNA Structure
Video Picture 51
Homework: Read 9.1-9.2
Review questions 1-6
Lab DNA extraction
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 9.3
Answer Discussion Questions 7-16
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/
Review discussion questions
Review previous lectures
Critical Thinking Questions in class
Practice test
Complete Study Guide
Post test DNA structure and replication
Work on Presentations
Work on presentations
Presentations Day 1
Presentations day 2
Resources
Lewis, R. 2010. Human Genetics Concepts and Applications ninth addition. McGrawHill. 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.com
http://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)
Overview
In 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.
StandardsB.1.26
B.1.27
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.
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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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.
-DNA is a double helix composed of complimentary strands
Procedures
Engage
Begin 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.
Explore
The 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/ Elaboration
After 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.
Materials
Power Point- DNA structure
Lab- DNA Necklace Kit (Carolina)
Power Point DNA Structure
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#2 Historical figures (1 day)
Overview
In 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.
StandardsB.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.
Procedures
Engage
Begin 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.
Explore
The 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/ Elaboration
On 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 Board
Informal- Asking engaging questions to each student during the lecture
Materials
Power Point- Historical Figures
Moodle- Journal entry
Power Point Historical Figures
#3 Replication and Mutation (1 day)
Overview
In 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.
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.
Objectives
Students 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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Procedures
Engage
Begin 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?
Explore
During 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.
Explanation
The 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).
Elaboration
After 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
Resources
Power Point DNA replication and Mutation
Web site www.bubbl.com
Online tutorials
http://highered.mcgraw-hill.com/sites/0073525278/
http://highered.mcgraw-hill.com/sites/0073525278/
#4 Presentations (4 days)
Overview
In 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.
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.
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.
B.1.27
Procedures
Engage
I 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.
Explore
Students 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/Elaboration
The 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
Resources
Presentation 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 Skills
In 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 1
Kary 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
d. Avery, MacLeod, and McCarty
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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
Question 10
If a DNA molecule contains 20% A, approximately what percentage of G is present?
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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
d. adenine
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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
b. A - C
c. G - T
d. A - T
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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
b. dispersive
c. semiconservative
d. semidispersive
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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:
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
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Watson and Crick based their conclusion that DNA is a double helix on results of
physical 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 labeled
DNA 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.
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.
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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.
Question 15
______ first noted an acidic substance in the nuclei of cells from pus.
Choose one answer.
a. Watson
b. Mendel
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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.
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.
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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
Question 25
The enzyme that inserts the correct bases in a growing nucleotide chain in a replicating
DNA molecule is:
a. Ligase.
b. DNA polymerase.
c. RNA polymerase.
d. Topoisomerase.
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Charts
Pretest
Post-test
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Pretest verses Post-test
Presentation Bar graph
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Narrative Statements
Unit Narrative
Standards used
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,
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different from all others. Likewise, understand that every other species has its own
characteristic DNA sequence
Students of different abilities
In 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 Thinking
In 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
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
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-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
Technology
Power 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
Directions
When 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
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.
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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 Applications
In 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 project
The 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.
Changes Based on Pretest
After 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.
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Project
The 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-test
The 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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