Download Genetics Review

Genetics and Heredity
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DIRECTIONS:
▪ Submit this test at the beginning of class on Tuesday, May 20, having this sheet attached to the
front of your work.
▪ Use a punnett square to aid your explanations for questions regarding crosses.
▪ If you choose to work with someone else, be sure to include their name(s) at the top of your answer
sheet. YOU SHOULD NEVER HAVE ANSWERS THAT ARE EXACTLY THE SAME - you are
discussing the answers yet writing them on your own!
----------------------------------------------------------------------------A. Matching: (10)
Match the statements in column A with the most appropriate answer in column B.
Column A
Column B
1.
Two or more alternate forms or versions of a gene
A. Phenotype
2. A genotype in which the alleles are different
B. Genes
3. Refers to the physical traits of an organism
C. Alleles
4. The passage of traits from parent to offspring
D. Recessive
5. Has an unexpressed allele that could be passed on to offspring
E. Dominant
6. A genotype in which the alleles are the same
F. Genotype
7. The gene-code that an organism contains
G. Heterozygous
8. The allele that is overshadowed by another
H. Carrier
9. The allele that determines the trait in the offspring
I. Heredity
10. Units of instruction, located on chromosomes, that produce or influence a
J. Homozygous
specific trait in the offspring
B. Multiple Choice: (5)
Choose the response that best answers the question
_____ 1. A gene exists in two different allele forms (A and a). What type of gametes can a homozygous recessive
individual produce?
(a) Aa (b) A (c) a (d) A and A
_____ 2. Familial intestinal polyposis results in multiple finger-like growths (polyps) from the lining of the large
intestine. It is inherited as a dominate trait. One parent is Pp and the other is pp. If the couple has four kids, how
many would be expected to have familial intestinal
polyopsis phenotypes?
(a) 1
(b) 2
(c) 3
(d) 4
_____ 3. If a human zygote has a X and a Y chromosome, it will normally be described as a
(a) female (b) male (c) sterile male (d) lethal gene
_____ 4. A cross was made between two black, rough-haired guinea pigs; the resulting offspring included six black
rough hair and one white rough
hair. From this information it can be assumed that
(a) one of the parents carried the gene for white hair
(b) both parents carried the gene for white hair
(c) the color gene shows incomplete dominance
(d) white hair is the dominant trait
_____ 5. When both parents are heterozygous for both traits in a dihybrid cross, what is the general ratio for
phenotypes of the offspring?
(a) 1:1 (b) 1:2:1:2:4:1:2:1:2 (c) 1:1:1:1 (d) 9:3:3:1
C. Short Answer: (20)
1. How would you determine if a pea plant with green pods (dominant phenotype) was homozygous? Explain. (3)
2. A flower grower is looking for new varieties of petunias. He crosses a yellow flower plant with a blue one and gets
green flowered plants. Explain how this is possible. (2)
3. In a monohybrid cross between homozygous dominant and homozygous recessive parents, there are 32 offspring in
the F2 generation. How many of the offspring would you expect to show the recessive trait? (2)
4. Would a skin cell mutation on your hand affect your offspring? Explain. (2)
5. What are polygenic traits? (2)
6. Explain what is meant by the term multiple alleles. (2)
7. Why are there more males with sex-linked problems than females? (2)
8. In a certain animal, a breed is known that always has a hairy tail; another breed is known that always has a naked
tail. How would you determine which trait is dominant? (3)
9. Why are calico cats always female? (2)
C. Genetic Problems: (20)
1. In guinea pigs, a rough coat is dominant over a smooth coat. A rough-coated guinea pig is bred to a smooth one,
giving eight rough and seven smooth offspring in the F 1 generation. What are the genotypes of the parents and their
offspring? (4)
2. In the fruit fly Drosophila melangaster, wrinkled wings and hairy body are produced by two recessive alleles
located on different chromosomes. The normal alleles, for long wings and hairless body, are dominant. Suppose a
wrinkled-winged hairy male is crossed with a homozygous normal female. What will be the ratios for the F1 and F2
generations? (both genotypes and phenotypes) (4)
3. A man and his wife both have normal color vision, but their daughter has red-green color blindness, a sex-linked
recessive trait. The man sues his wife for divorce on grounds of infidelity. Can genetics provide evidence supporting
his case? If yes, what evidence? (4)
4. Both Mrs. Smith and Mrs. Jones had babies the same day in the same hospital. Mrs. Smith took home a baby girl,
whom she named Shirley. Mrs. Jones took home a baby girl, whom she named Jane. Mrs. Jones began to suspect,
however, that here child had been accidentally switched with the Smith baby in the nursery. Blood tests were made:
Mr. Smith was type A, Mrs. Smith type B, Mr. Jones type A, Mrs. Jones type A, Shirley Type O and Jane Type B.
Had a mix-up occurred? (4)
5. A women having blood type A marries a man with blood type B. They have five children. Two sons having blood type
O, one daughter having blood type AB, one daughter with type A and the last daughter with B.
(a) Draw a pedigree of the family. (2)
(b) Indicate in the pedigree symbols the genotypes of all members and their phenotypes. (2)