1. A couple who are both carriers of the recessive gene for cystic fibrosis have two children who have cystic fibrosis. What is the probability that their next child will have cystic fibrosis?

2. A couple who are both carriers for the gene for cystic fibrosis have two children who have cystic fibrosis. What is the probability that their next child will be phenotypically normal?

3. In crossing a homozygous recessive with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the F1 generation?

4. In snapdragons, heterozygotes have pink flowers, whereas homozygotes have either red or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?

A woman and her husband both show the normal phenotype for pigmentation, but both had one parent who was an albino. Albinism is an autosomal recessive trait.

5. What is the probability that their first child will be an albino?

6. If their first two children have normal pigmentation, what is the chance that their third child will be an albino?

7. What is the chance that their fourth child will have a homozygous genotype?

8. Which of the following is an example of polygenic inheritance?

9. In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes.

When two roan cattle are crossed, the phenotypes of the progeny are found to be in the ratio of 1 red:2 roan:1 white. Which of the following crosses could produce the highest percentage of roan cattle?

The height of pea plants can be genotypically and phenotypically represented in the following ways:

10. Cross both homozygous dwarf parents.

11. Cross one homozygous tall parent with one homozygous dwarf parent.

12. Cross one heterozygous tall parent with one homozygous dwarf parent.

Assume that in guinea pigs short hair (SS or Ss) is dominant over long hair (ss).

Supply the information for the F1 progeny for each of the following categories:

13. Cross one heterozygous short haired guinea pig with one that is homozygous long haired.

14. Cross both homozygous long haired parents.

15. If a male which is heterozygous for coat length is mated with a similar female, what % of the progeny will have long hair?

16. If a male which is heterozygous for eye color is mated with a blue eyed female, what % of the progeny will have blue eyes?

Consider the following genotypes and phenotypes for pea seed color and texture:

17. Cross two pea plants that are heterozygous for each of the traits and show the F1 phenotypic ratio.

18. Cross one pea plant that is homozygous dominant for both traits with one that is homozygous recessive for each trait and show the phenotypic ratio of the F1 generation.

19. Cross a pea plant that is heterozygous for each trait with one that is homozygous dominant for the seed color, but heterozygous for the seed texture. Give the phenotypic ratio for the F1.

Use the information given below to answer the following question(s).

A woman who belongs to blood group A has a daughter who is Type O and a son who is Type B.

20. What is the genotype for the son?

21. What is the genotype for the mother?

22. What is the phenotype for the father?

Refer to the terms shown below to answer the following question(s).Each term may be used once, more than once, or not at all.

1. incomplete dominance

2. multiple alleles

3. dominance

4. recessivness

5. penetrance

23. The ability of a single gene to express its phenotype in a heterozygote .

a. 1

b. 2

c. 3

d. 4

e. 5

24. One example is the ABO blood group system.

a. 1

b. 2

c. 3

d. 4

e. 5

25. The phenotype of the heterozygote differs from the phenotypes of both homozygotes.

a. 1

b. 2

c. 3

d. 4

e. 5

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Use the choices shown below to answer the following question(s). Each choice may be used once, more than once, or not at all.

1. Huntington's disease

2. Tay-Sachs disease

3. phenylketonuria

4. hemophilia

5. sickle-cell anemia

26. Effects of this recessive single gene can be completely overcome by regulating the diet of the affected individual.

a. 1

b. 2

c. 3

d. 4

e. 5

27. This is caused by a dominant single gene defect affecting the nervous system and generally does not appear until the individual is 30-40 years of age.

a. 1

b. 2

c. 3

d. 4

e. 5

28. Individuals with this disorder are missing a specific clotting factor in the blood, making them susceptible to dangerous bleeding episodes.

a. 1

b. 2

c. 3

d. 4

e. 5

29. Substitution of the "wrong" amino acid in the hemoglobin protein results in this disorder.

a. 1

b. 2

c. 3

d. 4

e. 5

30. If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent?

A. AA

B. Aa

C. aa

D. The answer cannot be determined from this information.

31. Which is NOT true according to Mendel's law of segregation?

A. Each individual contains two factors for each trait.

B. One factor must be dominant and one factor recessive in each individual.

C. Factors separate from each other during gamete formation.

D. Each gamete contains one copy of each factor.

E. Fertilization restores the presence of two factors.

32. If you had two guinea pigs of opposite sex, both homoygous, one black and one brown, but you didn't know which was the dominant characteristic, how would you find out the dominant color?

A. Mate them together and see what color the offspring are, that will be the dominant color.

B. Mate them together and see what color the offspring are, the other will be the dominant color.

C. Mate them together, then mate their offspring to see what color the the grandchildren are, that will be the dominant color.

D. Mate them together, then mate their offspring to see what color the grandchildren are, the other color will be the dominant color.

E. None of the above.

33. What are alleles?

A. genes for different traits, such as hair color or eye color.

B. altemative forms of a gene for a single trait, such as blue eyes or brown eyes.

C. the locations of genes on a chromosome.

D. recessive forms of a kind of characteristic carried by genes.

E. dominant forms of a kind of characteristic carried by genes.

34. What causes Down syndrome?

A. the lack of pigment production

B. an extra chromosome 21

C. the presence of two different codominant alleles

D. inability to produce normal connective tissue

E. the environment interacting with the genotype

35. What causes type AB blood?

A. the lack of pigment production

B. an extra chromosome 21

C. the presence of two different codominant alleles

D. inability to produce normal connective tissue

E. the environment interacting with the genotype

36. Which disease results in deformed red blood cells, poor circulation, and anemia?

A. male pattern baldness

B. sickle-cell disease

C. Huntington disease

D. hemophilia

E. Duchenne muscular dystrophy

37. Cross a heterozygous female with normal color vision with a normal color visioned male. Will any of the female offspring be colorblind?

38. Cross a heterozygous female with normal color vision with a colorblind male. Will any of the female offspring be colorblind?

P1

39. AB x OO

a. Type A _____

b. Type B _____

c. Type AB _____

d. Type O _____

P1

40. AO x BO

a. Type A _____

b. Type B _____

c. Type AB _____

d. Type O _____

41. In sheep white color is due to a dominant gene (W), black is its recessive allele (w). A white ewe mated to a white ram produces a black lamb. If they produce another offspring, could it be white? (Yes/No) List the genotypes of all the animals listed in the problem.

a.white ewe___________

b.white ram___________

c.black lamb___________

Write the definitions for the following terms:

42. Dominant

43. Recessive

44. Phenotypic Ratio

45. Genotypic ratio

46. Meiosis

47. Gametes

48. Codominance

49. Incomplete Dominance

50. Alleles

51. Carrier

52. Homozygous

53. Heterozygous

54. Diploid

55. Multiple Alleles