Download Chapter 8 Quiz Review

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Date:________ Hour:_______
Chapter 8 Quiz Review
Directions: The vocabulary terms listed below are important terms for you to study and know for your quiz. However, it is
not required that you define them on this review sheet.
- Heredity
- Genetics
- Monohybrid cross
- True-breeding
- P generation
- F1 generation
- F2 generation
- Allele
- Homozygous
- Heterozygous
- Genotype
- Phenotype
- Law of segregation
- Law of independent assortment
- Punnett square
- Dominant
- Recessive
- Sex-linked trait
- Polygenic trait
- Incomplete dominance
- Codominance
- Multiple alleles
- Pedigree
- Probability
- Test cross
Directions: Answer the questions below as completely as possible.
1. Who was Gregor Mendel? Describe Mendel’s breeding experiments. (pg 160)
2. How did Mendel’s experiments differ from T.A. Knight’s breeding experiments? (pg 160-161)
3. Why are garden peas a good subject for studying heredity? Which seven traits did Mendel study in garden peas?
(pg 161)
4. What were the three steps of Mendel’s breeding experiments? What results did Mendel obtain from his
experiments? (pg 162)
5. Which four hypotheses did Mendel develop based upon the results of his breeding experiments? (pg 164-165)
6. Describe the law of segregation and draw a diagram illustrating the law. (pg 167)
7. Describe the law of independent assortment and draw a diagram illustrating the law. (pg 167)
8. White squash is dominant to yellow squash. Provide the genotype and phenotype of a heterozygous individual.
9. What is the purpose of a test cross? (pg 170)
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10. What is the difference between autosomal and sex-linked traits? Why do males inherit sex-linked traits more often
than females? (pg 173)
11. What is a polygenic trait and what are some examples of polygenic traits? (pg 175)
12. Provide an example of incomplete dominance. (pg 175)
13. How does codominance differ from incomplete dominance? (pg 177)
14. Describe how blood type is inherited in humans. Which alleles control blood type? (pg 177)
15. What is the role of the environment in an individual’s phenotype? (pg 177)
16. How are the following disorders inherited: sickle cell anemia, hemophilia, and Huntington’s disease? (pg 178-179)
17. How are genetic disorders detected and treated?
Punnett Square Problems
For extra help with Punnett square problems refer to the following problems in the Chapter 8 review section of your
textbook (pgs 182-183): #’s 6, 11, 17, 18, 19, 20 & 21.
1. Sickle cell anemia is a recessive genetic disorder. If a heterozygous female is married to a normal male, what is
the probability of them having a child with sickle cell anemia? Show Punnett square.
2. Tay Sach’s is a recessive genetic disorder. If two individuals are both carriers (heterozygous for Tay Sach’s, what
is the probability of them having a child with the disorder? Show Punnett square.
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3. Dwarfism is a dominant genetic disorder. If a heterozygous male is married to a normal female, what is the
probability of them having a child with dwarfism? Show Punnett square.
4. Buckshot and his bride, Bobbie-gene are thinking of having children. Buckshot suffers from a recessive genetic
disease called mountain madness (mm). Bobbie-gene had a brother with mountain-madness, so she figures that
she is a carrier (heterozygous). Is there a possibility that they can have a child without this disease? What is the
possibility of their child being a carrier? Is there any possibility of having a “normal” child? Show the Punnett
square that you used to determine these probabilities.
5. Normal thumbs are dominant to hitchhiker’s thumbs. If an individual who is homozygous for normal thumbs is
crossed with a heterozygous individual, what will the genotype and phenotype ratios be in the offspring? Show
Punnett square.
6. In humans, hair texture is controlled by incomplete dominance. A curly haired individual and a straight haired
individual have all wavy haired children. If two wavy haired people have children, what will the phenotypic and
genotypic ratios be? Show the Punnett squares you used to determine these ratios.
7. Colorblindness is inherited as a sex-linked recessive disease. An affected male marries a heterozygous female.
Draw a Punnett square of the possible offspring. What is the chance that they will have an affected child? Could
any of their daughters be affected?
Pedigree Problems
For extra help with Punnett square problems refer to the following problems in the Chapter 8 review section of your
textbook (pgs 182-183): #10. You may also want to work through the Data Lab on pg 174 of your textbook.
1. Draw the following pedigree in the space below. Albinism is a recessive trait.
“One couple has a son and daughter with normal pigmentation and a son that is an albino. Another couple has one
son and two daughters with normal pigmentation. The daughter from the first couple has three children with the son
of the second couple. Their son and one daughter have albinism; their other daughter has normal pigmentation.”
a. Label the generations and each individual in the pedigree.
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b. Determine the exact genotypes of as many individuals as possible. If an individual has more than one
possible genotype, indicate all possible genotypes for that individual.
2. The pedigree below shows the inheritance of Duchenne muscular dystrophy. Duchenne muscular dystrophy is a
recessive sex-linked disorder.
XD = normal
Xd = the trait (allele for muscular dystrophy)
Y = Y chromosome
a. What is the genotype of a male who has muscular dystrophy?
b. What is the genotype of a female
who has muscular dystrophy?
c.
What is the genotype of a female
carrier for muscular dystrophy?
d. How do you know that this pedigree
shows the inheritance of a sexlinked trait?
3. The pedigree below is for myopia (solid symbols), a fairly common, simply inherited human trait for nearsightedness occurring with equal-frequency in both sexes.
a. Is the allele controlling the
expression of myopia
dominant or recessive to the
allele for normal sight? How
do you know this?
b. Give the genotypes for all
individuals. If an individual
has more than one possible
genotype, indicate all possible
genotypes for that individual.