Mouse Genetics Student Worksheet Honors
Vocabulary: allele, DNA, dominant allele, gene, genotype, heredity, heterozygous, homozygous, hybrid, inheritance, phenotype, Punnett square, recessive allele, trait
Vocab sheet
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Mouse Genetics Student Worksheet Honors
Vocabulary: allele, DNA, dominant allele, gene, genotype, heredity, heterozygous, homozygous, hybrid, inheritance, phenotype, Punnett square, recessive allele, trait
Vocab sheet is included as a resource in this section of the Biology Content
Warm-up
1. Drag two black mice into the Parent 1 and Parent 2 boxes. Click Breed several times. What do the offspring look like?
What I noticed about the offspring’s of the pure bred black mice is that the offspring where black also because both the parents where pure black mice so the kids are going to be as well.
2. Click Clear, and drag two white mice into the parent boxes. Click Breed several times. What is the phenotype of the offspring now?
3. Do you think mouse offspring will always look like their parents?
Explain:
Activity A:
Patterns of inheritance Get the Gizmo ready:
•
Question: What patterns are shown by offspring traits?
1. Predict: What do you think the offspring of a black mouse and a white mouse will look like?
2. Observe: Click Breed several times. What do you see?
3. Observe: Drag two offspring into the Holding Cages. These mice are called hybrids because their parents had different traits.
What do you see now?
4. Experiment: Turn on Show statistics. Click Breed until there are 100 offspring.
5. Explore: Try other combinations of mouse parents. Write the results of each experiment in your notes. When you have finished, answer the following questions. (Note: You can refer to the parents as “pure black,” “pure white,” or “hybrid.”)
A. Which parent combination(s) yield only white offspring? “Pure White”
B. Which parent combination(s) yield only black offspring? “Pure Black”
C. Which parent combination(s) yield a mixture of black and white offspring? “Hybrid”
6. Challenge: Based on experiments similar to these, Gregor Mendel devised a theory of inheritance. Use your own observations to come up with your own explanation of how a trait such as fur color is passed down from parents to offspring.
Write your explanation below and then discuss your theory with your classmates above and below you using the chat. Revise your explanation if necessary.
Activity B:
Genetics Basics Get the Gizmo ready:
• Click Clear.
• Drag a black mouse and a white mouse into the parent boxes.
Introduction: Inherited traits are encoded on a molecule called DNA (deoxyribonucleic acid). Genes are segments of DNA that control a particular trait. Most genes have several different versions, or alleles. The genotype is the allele combination an organism has.
Question: How do alleles determine fur color?
1. Observe: Turn on Show genotype. Move your cursor over a mouse to see its genotype.
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A. What is the genotype of the black parent?
These mice are homozygous for fur color, meaning both alleles are the same.
B. Click Breed. What is the genotype of the offspring mice
These mice are heterozygous for fur color, meaning the alleles are different.
2. Analyze: Dominant alleles are always expressed when present. Recessive alleles are not expressed when the dominant allele is also present. Look at the two alleles for fur color.
A. Which allele is dominant, and which fur color does it produce?
B. Which allele is recessive, and which fur color does it produce?
3. Predict: Place two of the Ff offspring into the Holding Cages. Click Clear, and then place them into the parent boxes.
A. Which allele(s) could the offspring inherit from parent 1?
B. Which allele(s) could the offspring inherit from parent 2?
C. What are the possible genotypes of the offspring?
4. Experiment: Click Breed several times, and look at the genotypes of the offspring. Did you find all the predicted genotypes? Explain. Yes I did I also found ff in the white offspring’s though
Activity C:
Modeling inheritance Get the Gizmo ready:
• Click Clear.
• Drag a black mouse and a white mouse into the parent boxes.
Question: How do scientists predict the genotypes of offspring?
1. Model: Scientists use a Punnett square to model the different possible offspring genotypes from a parent pair. The parent genotypes are written across the top and side of the square, as shown. The four possible offspring genotypes are then filled in.
The first square is filled in for you. Fill in the remaining squares.
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A. What are the genotypes of the offspring?
B. What percentage of the offspring will have black fur? 75% will have black fur
C. What percentage of the offspring will have white fur? 25% will have white fur.
2. Experiment: Click Breed several times. Were your predictions correct?
3. Model: Use the Punnett squares below to model each parent combination.
Parent 1: Heterozygous black
Parent 2: Heterozygous black
F f
f
Predicted % black offspring: ______
Predicted % white offspring: ______
Parent 1: Heterozygous black (Ff)
Parent 2: Homozygous white (ff)
Predicted % black offspring: __51____
Predicted % white offspring: __49____
4. Experiment: Turn on Show statistics and Show as approximate percentage. For each combination, breed approximately 500 offspring. Record the results in the table below.
(Hint: To obtain an Ff mouse, breed an FF mouse to an ff mouse. Place two Ff offspring into the holding cages, click Clear, and then drag the Ff mice into the parent boxes.)
5. Draw conclusions: How well did the Punnett squares predict the offspring percentages for each parent pair?
Making your thinking visible
6. Defend the claim below using the sentence starters and frames in order to explain what heredity is and how it works in mice. Use your OWN WORDS!
CLAIM Heredity is the passing on of traits from one generation (parent) to the next (offspring).
EVIDENCE
Pull evidence from your data recorded above. When a pure black mouse(FF) is bred with a pure white mouse(ff) their resulting offspring… are hybrid black mice
REASONING The are hybrid black mice examples of heredity in action because…
7. Do you think most traits are inherited the way mouse fur color is? Kind of
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