Download Unit Plan: Genetics Biology 9-12

Genetics Victoria
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Unit Plan: Genetics
Biology 9-12
Victoria Spera
3/2011
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Title: Genetics
The study of the molecular structure and function of genes, heredity, variation and its
contribution to biotechnology. The discipline celebrates the work of Gregor Mendel and most
notably, James Watson and Francis Crick. Genetics also reinforces cell processes such as mitosis
and meiosis as well as provides a transition into concepts of evolution.
Abstract:
The unit to follow covers the foundational elements for the understanding of Genetics. The
underlining concepts outlined include: inheritance patterns, the structure and function of DNA
and RNA in replication and protein synthesis, the use of laboratory technology to extract DNA
from a strawberry, certain types of genetic and chromosomal mutations in humans and the use
and ethical issues surrounding genetically modified organisms (GMOs). In a nutshell, the
overall concepts covered are inheritance, DNA & RNA, human genetics and genetic engineering.
The concepts covered in this unit are organized in such a way that students engage in hands-on
inquiry-based learning. Each lesson focuses on students constructing their own knowledge and
understanding of genetics as scientists have encountered it and how they experience it every day.
With that said, you will find lessons that are student-centered, hands-on and that incorporate
elements of cooperative group work.
Rationale:
Genetics holds a very central role in the biological sciences and is very interdisciplinary in
nature as it pulls upon concepts of chemistry. Genetics also provides an explanation for who we
are, why we look the way we do and what connects us with our relatives; this is an exciting
venture in itself. Genetics also lends itself well to problem solving, the use of models in science
and to the application of science to society, technology and medicine. DNA is a very unique
discovery as it helps us identify people, helps explain why some of us have blue eyes and others
brown, it helps to explain why and how some of us may inherit sickle cell anemia, how high
cholesterol is connected to a particular change in our DNA sequence and the uses that this
information has for scientists that try and alter the genome.
More specifically, students encounter with Mendelian genetics and inheritance patterns exposes
them to the importance of trials, experimentation, patterns, probabilities, ratios and problem
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solving skills. Furthermore, the use of punnett squares, Mendels law of segregation and ratios
enables students to understand the usefulness of rules, laws and procedures when working out a
problem. I feel strongly that if there were one thing that our youth needs to take away from
learning is the ability to take information and problem solve accordingly.
In science it is also important to work as scientists do and scientists oftentimes construct models
that represent scientific concepts and phenomena that are intangible and unobservable to the
naked eye. Just as Watson and Crick created a life-size model of DNA, students will construct
their own DNA models that accurately represent its structure and reflect its function.
Understanding the process of protein synthesis is crucial as it lays the foundation for how our
body makes proteins, where mutations occur and how geneticists go about utilizing
biotechnology and genetic engineering. Students must understand the basic principles of
DNA/RNA structure and function in order to engage in higher order thinking. Understanding this
also reinforces what students have learned previously about the cell and organelle structure and
function.
As mentioned previously, genetics lends itself well to real-world applications as students can
apply their understanding of science to instances of cancer, disease, phenotypic diversity and
inheritance. Furthermore, students can understand the concept of recombinant DNA as it pertains
to their own diet, their own ethics, diverse perspectives, the environment and the economy. This
creates an underlining importance behind genetics and its supporting principles. Students must
illustrate a level of scientific literacy to rationally assess societal decisions. With that said,
students are able to build their problem-solving skills and think critically about science in an
array of settings.
Goals/Objectives:
SC.912.L.16.16 - Describe the process of meiosis, including independent assortment and
crossing over.
SC.912.N.3.5 - Describe the function of models in science, and identify the wide range of
models used in science.
SC.912.L.16.1 - Use Mendel's laws of segregation and independent assortment to analyze
patterns of inheritance.
SC.912.L.16.2 - Discuss observed inheritance patterns caused by various modes of inheritance,
including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles.
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SC.7.L.16.1 - Understand and explain that every organism requires a set of instructions that
specifies its traits,that this hereditary information (DNA) contains genes located in the
chromosomes of each cell, and that heredity is the passage of these instructions from one
generation to another.
SC.912.N.3.5 - Describe the function of models in science, and identify the wide range of
models used in science.
SC.912.L.16.3 - Describe the basic process of DNA replication and how it relates to the
transmission and conservation of the genetic information.
SC.7.L.16.1 - Understand and explain that every organism requires a set of instructions that
specifies its traits, that this hereditary information (DNA) contains genes located in the
chromosomes of each cell, and that heredity is the passage of these instructions from one
generation to another.
SC.912.L.16.10 - Evaluate the impact of biotechnology on the individual, society and the
environment, including medical and ethical issues.
SC.912.N.1 - Define a problem based on a specific body of knowledge, for example: biology,
chemistry, physics, and earth/space science
SC.912.N.4.2 - Weigh the merits of alternative strategies for solving a specific societal problem
by comparing a number of different costs and benefits, such as human, economic, and
SC.912.L.16.4 - Explain how mutations in the DNA sequence may or may not result in
phenotypic change. Explain how mutations in gametes may result in phenotypic changes in
offspring.
SC.912.L.15.15 - Describe how mutation and genetic recombination increase genetic variation.
SC.912.L.16.5 - Explain the basic processes of transcription and translation, and how they result
in the expression of genes.
SC.912.N.1 - Define a problem based on a specific body of knowledge, for example: biology,
chemistry, physics, and earth/space science, and do the following:
1.
2.
3.
4.
5.
pose questions about the natural world,
conduct systematic observations,
examine books and other sources of information to see what is already known,
review what is known in light of empirical evidence,
plan investigations,
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6. use tools to gather, analyze, and interpret data (this includes the use of measurement in
metric and other systems, and also the generation and interpretation of graphical
representations of data, including data tables and graphs),
7. pose answers, explanations, or descriptions of events,
8. generate explanations that explicate or describe natural phenomena (inferences),
9. use appropriate evidence and reasoning to justify these explanations to others,
10. communicate results of scientific investigations, and
11. evaluate the merits of the explanations produced by others.
Day-to-Day Activities: 15 classes (48 minutes each)
Activities
Inheritance
Week 1
Patterns of inheritance
Day 1 & 2:
- Mendels Laws/Punnett Square Practice
- Students will refer back to their Meiosis posters to visual the inheritance of traits
DNA/RNA
Structure and Function of DNA
Day 3:
- Review D.A.R.T (Part I)
- Structure/Function of the DNA double helix (Notes)
- Begin Double Helix Activity (DNA cutouts/models)
Day 4:
- Complete Double Helix Activity
- Introduction to DNA Replication
i. DNA animation
ii. DNA rap song
DNA Replication
Day 5:
- Manipulating the process of DNA replication with DNA model cutouts
- Illustrating/labeling processes on poster paper.
Week 2
Day 6:
- Extracting DNA from a Strawberry (lab)
Structure and Function of RNA
Day 7:
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-
Differences between DNA & RNA/ Four Corners
Protein Synthesis
Day 8:
- Review D.A.R.T (Part II)
- Protein Synthesis (SmartBoard Illustration Notes)
- Polypeptide Activity
Day 9:
- Review using Classroom Response Clickers(TEFA)
Day 10:
- Test:
i. DNA/RNA structure
ii. DNA replication
iii.Protein Synthesis
Human Genetics
Week 3
Mutations
Day 11:
- Traits Bingo
- Types of Mutations (Slides)
- Sickle Cell Anemia Pretest
Day 12:
- Sickle Cell Anemia Chart: Genetic mutation (SmartBoard)
- Sickle Cell Anemia Posttest
Day 13:
- Karyotypes activity: Chromosomal mutations
Genetic Engineering
Day 14:
- Debate Preparation: Genetically Modified Organisms
i. Initial thoughts
ii. Chose a side
iii.Research information/develop argument
Day 15:
- Debate Preparation: Genetically Modified Organisms
i. Wrap up preparation/organize argument
ii. Hold Debate
iii.Final thoughts
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Vocabulary: heredity, genetics, purebred, hybrid, dominant, recessive, codominant, incomplete
dominance, sex-linked, pigment, alleles, gene, homozygous, heterozygous, gamete, genotype,
phenotype, segregation, assortment, pedigree, autosome, mutation, karyotype, trait, replication,
transcription, translation
Lesson One: Patterns of Inheritance (2 days)
Topic/Concepts:
-
Students will be able to determine the probability of inheriting certain traits. Students will
be able to explain the law of independent assortment as well as define genotype, F1 and F2
generations, heterozygous and homozygous, phenotype and distinguish between dominant
alleles and recessive alleles.
-
Students will apply what they know about laws of inheritance to their understanding of
instances of incomplete dominance and codominance.
Materials:
-
Large Paper
Inheritance questions/scenarios
Meiosis Posters completed in a previous unit.
Black Markers
Part I
Procedures:
1. Engage: begin the lesson addressing the following:
How do we look the way we look?
How many of you look just like your parents/siblings?
Have you ever wondered what your children would look like?
Show students a family portrait on the board of a family with several similar-looking
siblings and with some that look different.
How does this happen?
2. Explain: Students will review what they know about our genes and where they come
from in the process of meiosis. Adding to this will be the fact that each chromosome
inherited from our mom and from our dad contain an allele for a certain trait. Students
will be allowed to visualize this with their completed meiosis posters.
Explain to students and illustrate the differences between dominant alleles and recessive
alleles and how we identify them. Redraw the process of meiosis and trace the path of
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each allele from our dad and allele from our mom to reinforce this process. This will be
an opportunity to introduce students to the law of independent assortment.
Repeat this same process for an individual that inherits two of the same alleles and for an
individual that inherits two different alleles and define each instance as homozygous and
heterozygous respectively.
3. Explore: Students will then be instructed to work out their own Punnett Square problems
using large paper, markers and the following question types:
Question 1: In rabbits, black fur is dominant over white fur. Two rabbits who carry the
gene for white fur but have black fur are mated. What are the possible phenotypes and
genotypes of the offspring? What are the chances of each?
Genotype:
Phenotype:
Probability:
Question 2: In humans, straight toes is dominant over curled toes . What would be the
result of a cross between a recessive male(tt) and a heterozygous female(Tt)? What are
the possible phenotypes and genotypes of the offspring? What are the chances of each?
Genotype:
Phenotype:
Probability:
4. Evaluate: Students will then compare their problems with peers to assess their work and
the work of their peers.
Part II
1. Engage: The lesson will begin with a short demonstration mixing red and white paint in
one glass followed by mixing balsamic vinegar and oil in another glass.
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- What will happen if we mix the red paint and the pink paint/What do you see?
- What will happen if we mix the oil and vinegar/What do you see?
2. Explain: Define on the board what incomplete dominance and codominance mean in the
context of inheritance. Ask students to label each glass demonstration as either
incomplete dominance or codominance. Encourage students to provide their own
examples or situations that demonstrate these two inheritance patterns.
3. Explore: Students will continue with their Punnett Square probability practice but will
instead work out problems of incomplete dominance and codominance:
Question 1: In chestnut horses, their coat (hair) color can be reddish brown (AA), light
red/pink (Aa) and creamy white (aa). Fill in the punnett square and determine the
expected genotypes and phenotypes from crossing two heterozygous parents.
Genotype:
Phenotype:
Probability:
Is this an example of codominance or incomplete dominance?
Question 2: Camellia flowers can be red, white or white and red. The red color is
dominant. Fill in the punnett square and determine the expected genotypes and
phenotypes from crossing homozygous red and heterozygous red white parents.
Genotype:
Phenotype:
Probability:
Is this an example of codominance or incomplete dominance?
4. Evaluate: Again, students will compare their answers with peers to evaluate their own
work and the work of peers. The large poster paper will be handed in graded according
to the following rubric:
i. Correctly identified genotype for parents. (2pts)
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ii. Punnett Square filled out accurately. (4pts)
iii. Each genotype corresponds to its correct phenotype and probability (%). (9 pts)
iv. Correctly identified each scenario as codominance and/or incomplete dominance.
(1pt)
Lesson Two: DNA Double Helix and Replication
Topic/Concepts:
-
-
Students will illustrate the double helical structure of DNA, identify the components that
make up the backbone (phosphate group and five-ringed sugar) and each nucleotide (sugar,
phosphate and nitrogen base).
Students will learn and apply their knowledge of the base pairing rules between nitrogen
bases and classify each base as a purine and/or pyrimidine.
With understanding of the structure of DNA and use of their models, students will
manipulate the process of DNA replication; specifically semi-conservative replication and
will be able to distinguish between the template strand and new strand.
Materials:
-
Construction paper cutouts- 7 colors
Envelops
Glue/Tape
Markers
Large Paper
Student Project/DNA rap song:
http://www.youtube.com/watch?v=d1UPf7lXeO8&feature=related
Learn360 Video clip on DNA: http://www.learn360.com/ShowVideo.aspx?ID=144865
Learn360 Video clip on DNA replication:
http://www.learn360.com/ShowVideo.aspx?ID=144851
Procedures:
Part I: DNA double helix (2 days)
1. Students will come to class with their DNA/RNA handout (see example handout below)
Part I
In your textbook, read about the structure of DNA
Complete each statement.
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1.
2.
3.
4.
5.
6.
7.
8.
9.
_________________ and ______________________ were the first scientists responsible for constructing
a DNA model.
Proteins are made up of __________________________ .
There are twenty different types of __________________________ .
The message of the DNA code is information for building __________________________ .
Each set of three nitrogen bases that codes for an amino acid is known as a
__________________________ .
Adenine and Guanine belong to a group of compounds known as __________________.
Cytosine and Thymine are known as ______________________.
Chromosomes contain both DNA and Protein tightly packed together to form ___________.
Before a cell divides, it duplicates its DNA in a copying process called ________________.
Label the below diagram:
2. Instruct students to take out their DARTs and fill in what they can while the lesson
proceeds.
3. Engage: Include students in an open discussion to get students thinking about the topic,
connect to what they have learned about inheritance and identify any misconceptions:
- What is DNA and where can you find DNA in you?
- What have you heard about DNA and what would you like to know about DNA?
- Explain to students that what they learned about inheritance patterns comes down
to the fact that genes contain nothing more than instructions for making proteins and
this is what Gregor Mendel had realized in his study of pea plants.
- What are proteins?
- Transition from Gregor Mendel and the study of inheritance to Watson and Crick
studying the structure of DNA by building three-dimensional models of the
molecule.
- Explain to students that this is what scientists do; they create models that
represent abstract ideas or scientific phenomena that they cannot manipulate in its
real form.
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- Inform students that they will do what scientists have done and that is construct
their own DNA model in efforts to better understand its structure but first they must
know what makes up a DNA strand.
4. Explain/Direct teaching (Smartboard): Illustrate the DNA double helix, identify the
components of its backbone, and explain how the official name for DNA (deoxiribonucleic
acid) is derived from its 5-ringed sugar and how the base pairing rules link the two strands
together. Explain to students that it is referred to as a spiral ladder.
5. Explore/Investigate: Students will then work in pairs to assemble their DNA molecules one
nucleotide at a time. There will be precut backbones, bases, sugars and phosphates. Students
are responsible for assembling them in their correct location.
6. Once complete, students will leave their models in their designated envelopes and will be
instructed to watch video clips that will reinforce DNA structure and introduce the process
of DNA replication. The students will need to answer the following question based on the
video clip:
- What is DNA replication?
Part II: DNA replication (1 day)
1. Students will come to class with their DNA models and part I of their DNA/RNA D.A.R.T
complete.
2. The lesson will begin with a review of DNA structure while students are asked to label a
blank DNA molecule and link complimentary pairs.
3. Engage: Include students in an open discussion to get students thinking about the topic,
connect it to previously learned material and identify any misconceptions:
- What is the process of mitosis/how many cells/chromosomes do we begin with and
how many do we end with?
- When and where in our body does this happen?
- What must our DNA do before the cell divides into two new cells?
4. Explain/Direct teaching: on the smartboard, the three stages of replication are listed and
accompanied by illustrations.
5. Materials are then handed out along with students envelopes containing their models.
Students work in pairs to manipulate the process of replication using their models while I
circulate the classroom to assess students understanding and provide guidance when needed.
6. Explore: Once complete, students will then glue their models onto large paper and label their
final product according to the instructions on the board (rubric to follow).
7. Evaluate: Students will present their posters to the class while other students engage in peer
evaluation using one thumb up for good work and two thumbs up for excellent work.
8. The posters are turned in and assessed based on the below rubric:
Final Product (DNA Replication Poster) Rubric
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DNA Structure
Objective
DNA
Strands are
assembled
1 properly
DNA Replication
Points
Objective
Points
7 pts
Step 1 of
DNA
1 Replication
4 pts
Nitrogenous
bases are
circled in
2 red
2 pts
Step 2 of
DNA
2 replication
4 pts
Backbone
circled in
3 blue
2 pts
Step 3 of
DNA
3 replication
4 pts
Nucleotide
circled in
4 yellow
2 pts
Can
distinguish
between
new and
template
4 strands
3 pts
Hydrogen
bonds
5 labeled
2 pts
total
points:
total
points:
15
15
total points: 30
Lesson Three: Extracting DNA from a Strawberry
Topic/Concepts:
-
The idea that DNA is present in all living things will be reinforced as students extract DNA
from a strawberry.
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-
Students will apply their knowledge of the structure and function of DNA to a real world
scenario.
Students will be able to provide rationales behind why it would be useful to extract DNA
from an organism.
Scientific tools/technology used in extracting DNA from a strawberry
Materials:
-
Lab instructions/reflection questions
Safety Goggles
Aprons
heavy duty ziploc bag
1 strawberry (36 total)
10 mL DNA extraction buffer (soapy, salty water)
cheesecloth
funnel
50mL vial / test tube
glass rod, inoculating loop, or popsicle stick
20 mL ethanol
Procedures:
Lab Introduction:
1. Students will come to class with their DNA packets containing notes.
2. Lesson will begin by asking students why scientists would want to extract DNA from
organisms.
- Induce mutations
i.
Bigger produce
ii. Resistant crops
- Analyze the structure and sequence of DNA
- Identify genetic disorders and possible cures
3. Inform students that they will be extracting DNA from Strawberries. Why would scientists
want to do that?
4. Present Scenario:
“In the past two years, strawberry farms in Plant City, Florida have experienced winter
freezes that resulted in decreased strawberry production. Farmers have looked into
genetically modifying their strawberries to be more resistant to freeze. They have consulted
local biologists (you) to extract the DNA from their strawberries…”
5. A prelab demonstration will be done to ensure students understand safety requirements
(safety goggles) and precautions (glass rods).
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6. The class as a whole will discuss the functioning of lab materials including the purpose of
the buffer and ethanol. For example, students will be asked to provide an answer to the
following probing questions:
Why do we use soap to wash our dishes/why can’t we simply wash our dishes
with hot water?
Where have you heard the term buffer/to buff?
What is the outer cell membrane made of?
What is ethanol? Where do we use it?
What does it mean that ethanol is not soluble in water?
How does temperature affect solubility?
i.
Does sugar dissolve better in your hot cup of coffee or iced coffee?
DNA extraction lab: The lab will begin once all students have received their bins of materials
and their lab instructions/reflection questions; have their safety goggles over their eyes and lab
jackets on. The lab will proceed in groups of four.
7. Students will begin by carefully smashing/grinding their strawberry inside of their Ziploc
bags for 2 minutes.
8. 10 ml of the buffer solution will be measured out by students but added to the bag by the
teacher and students will continue to mush/kneed the bag for 1 minute.
9. The filtration apparatus will be assembled and students will be instructed to pour the
strawberry slurry into it and allow it to drain into their test tubes.
10. The students will measure out 20 ml of cold ethanol and carefully pour it into their tubes and
observe.
- What happened/ What do you see?(introduce students to the term precipitate)
11. Students will then carefully dip their glass rods into their tubes where the strawberry extract
and ethanol come into contact and observe.
Example Lab questions:
1.
2.
3.
Match the procedure with its proper function:
Procedure
Function
a. Filter strawberry slurry through the cheesecloth ___ To precipitate DNA from solution
b. Mush strawberry with buffer solution
___ Separate components of the cell
c. Addition of ethanol to filtered extract
___ Break up proteins and dissolve
cell membranes.
What did the DNA look like? Relate what you know about the chemical structure of DNA
to what you observed.
Explain what happened in the final step when you added ethanol to your strawberry
extract.
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4.
5.
6.
A person cannot see a single cotton thread 100 feet away, but if you wound thousands of
threads together into a rope, it would be visible much farther away. Is this statement
analogous (a representation of) to our DNA extraction? Explain.
What are two important reasons that scientists would want to extract DNA from an
organism?
Is there DNA in your food? How do you know?
Lesson Four: DNA/RNA Four Corners
Topic/Concepts:
-
Students will understand the structure and function of both DNA and RNA by reviewing
their similarities and differences.
Materials:
-
DNA/RNA quo cards
Procedures:
1. Engage: The lesson will begin with a short review of DNA structure as students are
referred back to previously learned material and the video clips viewed days prior. An
analogy is used to illustrate the function of DNA in making our blueprint inside of our
cell’s nucleus. This is then generalized to our bodies need to make proteins. The
following questions are asked:
Where are proteins made?
What provides the instructions for making these proteins and where is it stuck?
How is the message passed along?
What is RNA/what types of RNA do we have?
What does it look like?
How does it compare to what we know about DNA?
2. Explain: Students are then instructed to copy down illustrations based on the information
provided by peers. The students are guided by the teacher while the teacher illustrates the
two nucleotide strands on the board and helps to identify the different types of RNA
molecules and their function.
3. Explore: The class will then participate in a game of four-corners using quo cards
containing terms that define DNA, that define RNA and that define both. One corner is
designated “DNA”, one corner “RNA, the other “Both” and the last “I don’t know”.
Each student is given a quo card and asked to go to their correct corner. The quo cards
contain an example of the following:
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Adenine pairs with Thymine
Contains the sugar
deoxyribose
Formed during transcription
Made up of a single strand
Can replicate itself
Within its molecule is the
“blueprint” that specifies how
proteins are made
Watson & Crick first
described is structure
Contains the sugar ribose
3 different types: messenger,
ribosomal and transfer
Made of nucleotides
Contains a sugar-phosphate
backbone
Cytosine pairs with Guanine
Adenine pairs with Uracil
4. Evaluate: Each student will read off their card and the class as a whole will assess
whether the student chose the correct corner and why. The “I don’t know” corner would
be addressed last in hopes that peer interaction and evaluation will help the student arrive
at the correct answer. If necessary, terms or concepts will be revisited should students
need elaboration.
Lesson five: Polypeptide Activity
Topic/Concepts:
-
Students will be able to model/simulate the process of transcription and translation as they
progress from a DNA sequence strand to a polypeptide chain/protein.
Materials:
-
DNA/RNA handout
Photocopied Sheets
Codon Wheel(textbook or photocopy)
Organelle labels (nucleus, ribosome and cytoplasm)
Procedures:
Students will come to class with their DNA/RNA handouts and will be responsible for
completing part II by the end of the class:
Part II
In your textbook, read about RNA and Protein Synthesis
Complete each statement.
1.
Proteins are made in the cytoplasm of a cell, whereas DNA is found only in the
__________________________ .
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2.
3.
4.
5.
6.
7.
8.
9.
The process of making RNA from DNA is called __________________________ .
The process of transcription is similar to the process of DNA __________________________ .
__________________________ carries information from the DNA in the nucleus out into the cytoplasm
of the cell.
mRNA carries the information for making proteins to the __________________________ .
The amino acid __________________________ is represented by the mRNA codon ACA.
________________________ and ________________________ are mRNA codons for phenylalanine.
There can be more than one __________________________ for the same amino acid.
______________________ , _____________________ , and _____________________ are stop codons.
____________________________ and __________________________ are amino acids that are each
represented by only one codon.
10. __________________is a nitrogenous base that can only be found in DNA where __________________ is
a nitrogenous base found only in RNA.
Label the below diagram:
1. Explain/Direct Teaching: Students will illustrate the different steps of protein synthesis in
their interactive notebooks while the steps are outlined/illustrated on the Smartboard.
2. Engage: The lesson will begin with student’s attention being directed to the part of the room
labeled nucleus followed by their desktops labeled ribosome and the center of the room
containing the ribosome as the cytoplasm. The students will be told that they will be
simulating the process of protein synthesis in pairs where one student will be the mRNA
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strand and the other the tRNA strand. The following instructions would be given in question
form:
- Which partner will go up to the nucleus and transcribe the DNA message strand?
- Where are proteins made?
- Where must the mRNA partner return to?
- Pointing to the box filled of amino acids at one of the desks in the cytoplasm: which
partner will need to retrieve the amino acids and bring it back to their ribosome?
- How will the tRNA partner know what to grab?
- How will you know when to stop?
- What is your final product?
3. Explore/Elaborate: Students will then begin simulating the process of protein synthesis
starting with the mRNA partner transcribing the DNA strand and returning it back to his/her
table (ribosome). The tRNA will then decode the codons on the mRNA strand in
complimentary anticodons before he/she gets up to retrieve the correct amino acids. The
tRNA and mRNA student will work together to figure out the correct amino acids based on
the codon wheel in their textbook. The process will be repeated until a STOP codon is
reached.
4. Explain/Evaluate: While the students work in pairs the teacher will reinforce students
knowledge of the material by engaging students in questions. Students will also need to be
able to interpret and use a codon wheel, distinguish between codons and anticodons, place
their amino acids in the correct sequence and label the bonds in between them. Each pair will
be responsible for consulting peers to compare their results and ensure that they have
understood the concepts required to successfully complete the assignment.
Lesson Six: Traits Bingo
Topic/Concepts:
-
Students will be introduced to mutations and how mutations occur in our gene sequence and
on our chromosomes.
Students will understand that mutations contribute to the diversity we see in organisms.
Students will be able to classify a mutation as harmful, beneficial or insignificant once they
are reminded that living organisms thrive to reproduce.
Students will be able to identify possible genotypes for certain phenotypic traits.
Materials:
- Bingo Sheets
- PTC paper
- Candy
- Colored pencils/markers
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-
Notebooks
Procedures:
1. Engage. The lesson will begin with the following discussion questions:
i. In the process of DNA replication or protein synthesis, do you think there are ever
any mistakes made?
ii. What do you think results in this/what is a mutation?
iii.Are mutations always bad/are they always passed on?
2. Explore/Elaborate. In efforts to answer these questions, students will participate in a traits
bingo game (see below) to explore different mutations that they can find in themselves
and others. These traits will not be termed mutations, but rather recessive and/or
dominant traits. Once each trait is explained and students identify whether they are
dominant for the trait or recessive for the trait, they will color their box and record the
possible genotype(s) for this trait.
B
I
N
G
O
I have a bent
little finger
I do not have
a dimpled chin
I cross my left
thumb over
my right
Straight
Hairline
Mother
Genotype:
Genotype:
Genotype:
I have
detached
earlobes
Genotype:
I cross my
right thumb
over my left.
Genotype:
I do not have
hitchhikers
thumb
Genotype:
I am a tongue
roller
Genotype:
I am a PTC
nontaster
My little
finger is
straight
Genotype:
FREE
Genotype:
I have mid
digital hair
Genotype:
Genotype:
I have blue
eyes
Genotype:
I am a PTC
taster
Genotype:
I do not have
blue eyes
Genotype:
I have
attached
earlobes
Genotype:
I have
hitchhikers
thumb
Genotype:
I have a
different trait
than the
person sitting
next to me.
I have freckles
Genotype:
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I am colorblind
Genotype:
I cannot roll
my tongue
Genotype:
I have a
dimpled chin
Genotype:
I have a
widows peak
Genotype:
I do not have
freckles
Genotype:
3. Explain: Once bingo has been reached. Students will be instructed to take brief notes on
the different types of mutations and will elaborate on the game by providing additional
examples of these mutations. The will be exposed to a Pedigree as diagram to map the
inheritance of mutations and karyotypes as a way to depict the genome of an individual.
More specifically, students will be shown the differences between a male and female
karyotypes and how to organize and interpret karyotypes.
4. Evaluate: Students are allowed to take home their bingo cards to review and closing the
class will be a brief pretest on Sickle Cell Anemia. This functions not only to help
students summarize what they have learned, but also assess their prior knowledge on the
topic before delving in the following day.
Sickle Cell Response Clicker Questions Pretest
1
Sickle Cell Anemia is considered:
a. A harmful mutation
b. A beneficial mutation
c. It depends.
d. I'm not sure
2
Sickle Cell Anemia effects:
a. The lungs
b. Red blood cells
c. White blood cells
d. I'm not sure
3
The blood is responsible for:
a. Carrying Carbon Dioxide to the body
b. Carrying Oxygen to the body organs
c. Producing hormones
d. I'm not sure
4
Sickle Cell Anemia is inherited.
a. True
b. False
5
c. I'm not sure
Is Sickle Cell Anemia more common in individuals of a certain
descent?
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a. Yes
b. No, anyone can inherit it.
c. I'm not sure
6
Sickle Cell Anemia is considered what type of mutation?
a. Genetic Mutation
b. Chromosomal Mutation
c. I'm not sure
Lesson Seven: Sickle Cell Anemia: Beneficial or Harmful?
Topic/Concepts:
-
Students will continue to explore the differences between types of mutations and distinguish
between those that are beneficial and those that are harmful.
Students will apply their knowledge of inheritance patterns, pedigrees and protein synthesis
to human genetics in efforts to construct their own understanding of genetic diseases.
Students will investigate the relationship between Sickle Cell Anemia and the Malaria
endemic.
Materials:
-
Sickle Cell Anemia Charts
Response Clicker Pre and Post test
Response Clickers
Slides
Procedures:
1. Engage. The lesson will begin by asking students the following questions as an open
discussion:
i. What they know about Sickle Cell Anemia?
ii. Do they know anyone with the disease?
iii.
What does this disease affect in the body?
iv.
What does our blood do?
v. How would we classify this disease: harmful or beneficial?
2. Explore/Explain. The lesson will proceed with students working out answers to their own
questions by filling out a chart divided into four boxes (see below). The boxes will
address the following:
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Sickle Cell Genotype:
Sickle Cell Phenotype:
Punnett Square Probability:
Relationship to Malaria:
i.
Sickle Cell Genotype: Students will need to transcribe and translate the DNA
strand of normal hemoglobin and defective hemoblogin. In this same box students
will also identify the genotypes for normal hemoglobin, sickle cell trait and the
sickle cell disease.
ii.
Sickle Cell Phenotype: Once students have established the change in one base in
the DNA strand (point mutation) and the resulting change in the amino acid coded
for, they will explain the physical differences between normal hemoglobin and
sickled hemoglobin. Students will also draw a picture in this box.
iii.
Punnett Square Probability: Students will be shown a pedigree and asked to figure
out the probability of carrying the sickle celled gene when crossing two
individuals who are carriers. Students should know that diagramming a Punnett
Square will provide them with these probabilities.
iv.
Relationship to Malaria: Before this box is filled in, students will be asked to
analyze a map showing the occurrence of Malaria next to a map showing the
occurrence of Sickle Cell Anemia and draw some conclusions. What is malaria?
How do we get Malaria? Where do we find Malaria most common in? Students
will be unaware of how the two relate but will be able to establish a relationship.
Students will then be responsible for creating a plus/delta for each genotype:
a. AA: +Normal Hemoglobin/-Resistance to Malaria
b. AS: 0 Mixed Hemoglobin/+ Resistance to Malaria
c. SS: -Defective Hemoglobin/+Resistance to Malaria
3. Elaborate. Following the completion of the squares, students will be asked to reflect and
decide based on their information, who makes out best in the situation( those with normal
hemoglobin, those with the sickle cell trait or those with the sickle cell disease) and why.
They will then be asked whether they think that Sickle Cell Anemia is a beneficial or
harmful mutation.
4. Evaluate. Closing the lesson will be a short 7-question post assessment using response
clickers. This will allow students to assess what they learned and provide feedback to the
teacher about what the students have learned and the effectiveness of the lesson.
Sickle Cell Response Clicker Example Questions
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1. The phenotype resulting in defective hemoglobin (Sickle Cell Anemia) is a result of what
type of Genetic Mutation:
a. Point Mutation
b. Frameshift mutation
c. Chromosomal mutation
2. The change of just one base on a DNA nucleotide in cases of Sickle Cell Anemia alters
the amino acid on normal hemoglobin from Glutamic Acid to:
a. Proline
b. Valine
c. Lysine
3. The sickling of hemoglobin is due to:
a. Hydrophilic regions on the hemoglobin
b. Hydrophobic regions of the molecule
4. Which genotype below represents an individual with the sickle cell trait?
a. SS
b. AS
c. AA
5. If two parents are heterozygous for the sickle cell trait(AS), then the probability of their
children having the sickle cell trait is:
a. 25%
b. 75%
c. 50%
6. Sickle cell trait provides a survival advantage in the face of which disease?
a. Influenza
b. HIV
c. Malaria
7. Sickle cell anemia is predominantly found in individuals who are of:
a. American descent
b. African descent
c. Asian descent
Lesson Eight: Karyotypes
Topic/Concepts:
-
Students will be able to interpret and construct their own karyotype in efforts to distinguish
between a normal male and female karyotype and those karyotpyes consisting of a
chromosomal abnormality: Down syndrome male, Down syndrome female, turners female
and klinefelters male.
Materials:
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-
Jumbled Karyotype Sheets
Scissors
Glue
Procedures:
1. Engage: The lesson will begin with a scenario projected up on the board to get students
thinking about chromosomal mutations in a real-life situation:
2. Explore/Explain: Before students begin the hands-on activity, a series of brief slides will
introduce students to the following in 5 brief Power Point slides:
- The explanation of nondisjunction
- Mapping the human genome using a karyotype
- Explanation of specific chromosomal abnormalities in humans:
i.
Down Syndrome
ii.
Turners Syndrome
iii.
Klinefelters Syndrome
The scenario will be put back u p on the board and students will transition into the
activity. Materials will be handed out and students will cut out their chromosomes,
arrange them onto lined paper in the correct order and label each chromosome.
3. Evaluate: Once complete, the students will be responsible for writing a brief diagnosis to
report to the inquiring couple.
- How will you diagnose this fetus?
- How do you know?
Lesson Nine: Genetically Modified Organisms
Topic/Concepts:
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-
Students will understand that genetically modified organisms (GMOs) are genomes that are
altered using recombinant technology.
Students will also be exposed to the different ethical issues surrounding biotechnology.
Materials:
-
-
Computer access
Debate Rubric
Following websites:
i. http://www.brighthub.com/science/genetics/articles/23358.aspx
ii. http://www.wholefoodsmarket.com/values/
iii.http://www.monsanto.com/products/pages/biotechnology.aspx
Three essential questions
i.
What is a genome?
ii.
What is a genetically modified organism?
iii.
What is recombinant DNA/technology?
Procedures:
1. Engage: To start the lesson, students will read over the following scenario and explain
what they know about the topic and how they feel about GMOs.
In efforts to address world hunger in third world countries, the
United States Government has decided to invest in genetically
modified rice crops locally and export them to third world
countries suffering from famine and poverty. This is done by
inserting engineered proteins into the rice genome to improve
nutritional value.
2. Explore: After the students have reflected and provided their own thoughts and opinion
about the scenario, they are assigned to a certain group and asked to argue for or against
genetically modified organisms on behalf of the group they are representing.
i. Nutritionist
ii. Economist
iii. Representative of Monsato
iv. Local organic farmer
In doing so, students will research websites and/or any articles to develop their argument
and will be required to identified the possible arguments of the other groups. Each
individual student will be responsible for turning in the following sheet:
Topic:
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For/Against:
Representative group:
Fact 1:
Source:
Expert Witness:
Fact 2:
Source:
Expert Witness:
Fact 3:
Source:
Expert Witness:
Fact 4:
Source:
Expert Witness:
In preparation for counter arguments:
Counter Argument:
Rebuttal:
Counter Argument:
Rebuttal:
Counter Argument:
Rebuttal:
They will be told that a debate will follow where they will be graded on the following
rubric:
CLASSROOM DEBATE RUBRIC
Levels of Performance
Criteria
1.
Organization
and Clarity:
1
2
3
4
Unclear in most
parts
Clear in some parts
but not over all
Most clear and
orderly in all
parts
Completely
clear and
orderly
presentation
Few or no
relevant reasons
given
Some relevant
reasons given
Most reasons
given: most
relevant
Most relevant
reasons given
in support
Viewpoints and
responses are
outlined both
clearly and
orderly.
2. Use of
Arguments:
Reasons are
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given to
support
viewpoint.
3. Use of
Examples and
Facts:
Few or no
relevant
supporting
examples/facts
Some relevant
examples/facts
given
Many
examples/facts
given: most
relevant
Many relevant
supporting
examples and
facts given
No effective
counterarguments made
Few effective
counterarguments made
Some effective
counterarguments made
Many effective
counterarguments
made
Few style
features were
used; not
convincingly
Few style features
were used
convincingly
All style features
were used, most
convincingly
All style
features were
used
convincingly
Examples and
facts are given
to support
reasons.
4. Use of
Rebuttal:
Arguments
made by the
other teams are
responded to
and dealt with
effectively.
5.
Presentation
Style:
Tone of voice,
use of gestures,
and level of
enthusiasm are
convincing to
audience.
3. Explain: Students will have access to the rubrics as they plan for their arguments to have
a clear understanding of what is expected of them. Following the debate, each group will
assess the other groups as a whole using the same rubric above. Once complete, the
rubrics will be given to each group to allow for immediate feedback from peers.
Final Assessment:
Assessing students on this unit will take on a more comprehensive approach as students
are assessed almost daily on their classroom activities, mini-projects, directed reading skills and
debate. Assessment in this sense takes the form of rubrics, levels of participation and completion
of work. There will be a more summative assessment administered following the DNA/RNA
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subunit as this contains the foundation for the entire unit. It is imperative that students retain,
apply, synthesize and evaluate upcoming concepts that require a sound grasp of DNA/RNA. In
addition to this, the DNA/RNA subunit is challenging and difficult. With that said, a review daywith use of response clickers- and a test day are factored into the unit.
The assessment’s format is multiple choice, matching, true/false and problem-solving. Two
separate forms are created; both containing a total of 25 questions (see sample test below).
Additionally, students are responsible for submitting their Unit notebooks that contain notes
taken during the class, vocabulary, video-clip questions and any other classroom activities. This
is also assessed. In doing so, students are responsible for submitting their notebooks with a table
of contents and need to be ordered correctly and organized.
DNA/RNA Test B
Multiple Choice: Choose the best answer.
1. To fit into the tiny nucleus of the cell, the long DNA strand must:
a. shrink
b. break
c. coil
2. What is the organelle found in the cell that provides the site for making protein?
a. ribosome
b. nucleus
c. endoplasmic reticulum
3. A Nucleotide consists of:
a. nitrogen base
b. sugar, phosphate and a nitrogen base
c. sugar and phosphate
4. The backbone of a DNA and RNA strand is made up of:
a. sugar, phosphate and nitrogen base
b. sugar
c. sugar and phosphate
5. Nitrogenous bases are bound together by:
a. covalent bonds
b. nitrogen bonds
c. hydrogen bonds
6. What is the official name for DNA?
a. Ribonucleic Acid
b. Deoxyribonucleic Acid
c. DoNotAnswer
7. DNA provides instructions for making what?
a. Ribosomes
b. Carbohydrates
c. Proteins
8. Ribonucleic acid is the official name for:
a. RNA
b. DNA
c. CJA
9. _______________ and _________________ were first responsible for identifying the structure of
DNA.
a. Watson & Crick
b. Topping and Hughes
c. Mendel & Darwin
10. How many bases make up a codon?
a.4
b. 3
c. 2
11. The process occurring in the nucleus where a complimentary RNA strand is created is known as:
a. Transcription
b. Replication
c. Translation
12. What would be the complimentary DNA strand for ATTCAG?
a. ATTCAG
b. UAAGUC
c. TAAGTC
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13. The tRNA anticodon for the DNA template strand ATGCCCTAG would be?
a. AUGCCCUAG
b. UACGGGAUC
c. ABCDEFGHIJK
14. The process that results in two identical DNA molecules is known as the process of:
a. Translation
b. Transcription
c. Replication
15. Protein is made up of a chain of:
a. amino acids
b. enzymes
c. DNA
Match the correct letter on the right with the term on the left.
16. tRNA
a. Transcribes the message of DNA and takes this message from inside the
nucleus out into the cytoplasm.
17. rRNA
b. Has a very specific structure that binds an amino acid at one end and the
mRNA at the other end.
18. mRNA
c. Located inside of the ribosomes where proteins are assembled.
Questions 19 & 20:
Using the Codon Wheel above:
19. The DNA base sequence, TAC, codes for which amino acid?
a. Stop
b. Methionine
c. Tyrosine
20. The mRNA base sequence, CCA, codes for which amino acid?
a. Proline
b. Glycine
c. Histidine
True/False: Identify whether the statement below is true or false.
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21. The process where amino acids are assembled into chains within ribosomes is known as
translation.
a. True
b. False
22. Only DNA contains nucleotides.
a. True
b. False
23. Transcription results in a new DNA strand.
a. True
b. False
24. RNA aids in protein synthesis.
a. True
b. False
25. DNA replication involves the enzyme DNA polymerase
a. True
b. False
Extra credit: Chose one question and provide a written answer.
a. The buffer in our DNA extraction lab had two specific functions. What were they?
b. What two bases are considered Purines and what two bases are considered Pyrimidines.
Resources
U.S. Department of Energy, Human Genome Project. (2003). Genetic disease profile: sickle cell anemia
Retrieved from genomics.energy.gov
DNA. Standard Deviants
1996 Retrieved March 23, 2011, from
Learn360: http://www.learn360.com/ShowVideo.aspx?ID=144865
Knauft, D. (2004). Strawberry dna extraction. Unpublished raw data, College of Agricutural and
Environmental Sciences, University of Georgia, Georgia. Retrieved from
http://www.uga.edu/discover/sbof/index.htm
Mitosis. Standard Deviants
1996 Retrieved March 23, 2011, from
Learn360: http://www.learn360.com/ShowVideo.aspx?ID=144851
Lesson plans inc. . (2007). Retrieved from http://www.lessonplansinc.com/
Postlethwait, J.H, & Hopson, J.L. (2006). Modern biology. Austin, Texas: Holt, Rinehart and Winston.
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