Genetics and Sex-Linked Inheritance Test Review
Matching:
______ 1. “This allele is only seen when paired with itself”
A. genotype
______ 2. JJ or jj
B. phenotype
______ 3. “An organism’s physical appearance or behavior”
C. homozygous
______ 4. “An allele that has more than one effect on an organism”
D. heterozygous
______ 5. “Several alleles, each contributing a small amount to the
final appearance of the trait”
E. allele
______ 6. “One dominant and one recessive allele”
F. dominant allele
______ 7. “An organism’s genetic makeup”
G. recessive allele
______ 8. “An allele that is always seen”
H. pleiotropy
______ 9. “A variation of a gene”
I. polygenic trait
______ 10. These are why there are 4 different blood types
J. multiple alleles
11. Mendel spoke of observing “true breeding” and “non-true breeding” plants. What did he mean by this?
How would modern geneticists explain what Mendel observed?
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12. Explain Mendel’s two Rules of Heredity. (Rule of Independent Assortment and Rule of Segregation).
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Complete a Punnett Square to support your answers for questions #13 – 16.
13. When Mendel crossed two purple-flowered pea plants, he obtained a phenotypic ratio of 3:1 (purple- flowered
pea plants to white-flowered pea plants). What were the genotypes of the parents?
14. All the polar icecaps have melted, covering the world in water. If a man with webbed fingers and webbed toes
marries and has children with a woman that is heterozygous for webbed fingers and webbed toes, what
genotypes will their children have? (Webbed fingers and toes are both recessive traits).
15. A cartoon mouse with 3 fingers mates with another cartoon mouse with 4 fingers. Predict the phenotypes of
their offspring if 5 fingers plus 3 fingers makes 4 fingers.
16. If mom has blood type AO and dad has blood type AB, what are the possible blood types of their children?
17. Is it possible for any of their grandchildren to be blood type OO? If so, how? If not, why not?
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18. Use the Rule of Multiplication to determine how many children in question #14 will be heterozygous for
webbed fingers and have webbed toes.
19. One of the newest areas of genetic research is epigenes. What is an epigene? What does it do?
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20. What do I mean when I say that a gene has been ‘imprinted’? How does imprinting affect an
individual? How, if at all, does it affect an individual’s offspring?
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21. Explain the process of DNA methylation. Include in your answer, when this process happens.
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22. What does siRNA do? Choose a disease that is being proposed for treatment using siRNA and
explain how this treatment might work.
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Matching:
______ 23. One gene modifies the effects of another gene
A. Autosome
______ 24. Proved that genes are carried on the sex chromosomes
B. Sex Chromosome
______ 25. The gain or loss of a chromosome
C. Nondisjunction
______ 26. Chromosomes that control the characteristics of the body
D. Thomas Morgan
______ 27. Chromosome pairs that don’t separate during meiosis
E. Walter Sutton
______ 28. An inactivated X chromosome
F. Barr body
______ 29. Credited with the chromosomal theory of inheritance
G. Epistasis
______ 30. Chromosomes responsible for gender characteristics
H. Aneuploidy
31. What is mitochondrial DNA? How does it affect inheritance?_______________________________________
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32. What is a Barr body? Why are they created? _____________________________________________________
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33. A child is born with the genotype XXY. What caused this? Is this child male or female? How do you know?
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34. A male grasshopper’s chromosome #3 has an inverse mutation. (This mutation causes the wings to be
misshapen). If the female has a normal but imprinted chromosome #3, describe the phenotype of the offspring.
the explain why this happened.
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