Genetics 1: Mendel and the Gene Idea

1) Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that

2) A plant with purple flowers is allowed to self-pollinate. Generation after generation, it produces purple flowers. This is an example of

3) What is the difference between a monohybrid cross and a dihybrid cross?

4) A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates

5) The F₁ offspring of Mendel's classic pea cross always looked like one of the two parental varieties because

6) Which of the following is (are) true for alleles?

b 7) What is genetic cross between an individual showing a dominant phenotype (but of unknown genotype) and a homozygous recessive individual called?

8) Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests

9) A 9:3:3:1 phenotypic ratio is characteristic of which of the following?

10) When crossing a homozygous recessive with a heterozygote, what is the chance of getting an offspring with the homozygous recessive phenotype?

11) P = purple, pp = white. The offspring of a cross between two heterozygous purple-flowering plants (Pp × Pp) results in

12) What are Punnett squares used for?

13) In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?

14) In a cross AaBbCc × AaBbCc, what is the probability of producing the genotype AABBCC?

15) A 1:2:1 phenotypic ratio in the F₂ generation of a monohybrid cross is a sign of

16) In snapdragons, heterozygotes have pink flowers, whereas homozygotes have 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?

17) In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (Rr) offspring of red (RR) and white (rr) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white?

18) Three babies were mixed up in a hospital. After consideration of the data below, which of the following represent the correct baby and parent combinations?

The questions below refer to the following terms. Each term may be used once, more than once, or not at all.

A. incomplete dominance

B. multiple alleles

C. pleiotropy

D. epistasis

19) the ability of a single gene to have multiple phenotypic effects

20) the ABO blood group system

21) the phenotype of the heterozygote differs from the phenotypes of both homozygotes

22) cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections

23) Which of the following is an example of polygenic inheritance?

24) Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by

Use the following information to answer the questions below.

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

25) What is the probability that their first child will be an albino?

26) If their first two children have normal pigmentation, what is the probability that their third child will be an albino?

27) A woman has six sons. The chance that her next child will be a daughter is

28) People with sickle-cell trait

29) When a disease is said to have a multifactorial basis, it means that

30) Which of the following terms is least related to the others?

The questions below will use the following answers. Each answer may be used once, more than once, or not at all.

A. Huntington's disease

B. Tay-Sachs disease

C. phenylketonuria

D. cystic fibrosis

E. sickle-cell disease

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

32) Individuals with this disorder are unable to metabolize certain lipids, affecting proper brain development. Affected individuals die in early childhood.

33) This is caused by a dominant single gene defect and generally does not appear until the individual is 35-45 years of age.

34) Effects of this recessive disorder can be completely overcome by regulating the diet of the affected individual.

35) This results from a defect in membrane proteins that normally function in chloride ion transport.

36) Which of the following techniques involves the preparation of a karyotype?

37) All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ________ to the allele for white flowers.

38. What does independent assortment refer to?

39.. If gene A prevents the expression of gene a, we say that gene A is:

40. According to Mendel's law of Independent Assortment this parent (AaBb) could produce all of these gametes except:

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

42. 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?

43. Black fur in mice(B) is dominant to brown fur (b). Short tails (T) is dominant to long tails (t). What proportion of the progeny of the cross BbTt x BBtt will have black fur and long tails?

44. What was the most significant conclusion that Gregor Mendel drew from his research?

45. The phenotype of an organism

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

46. Given the parents AABBCc x AabbCc, assume simple dominance and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent

47. Select the symbolism which best represent a heterozygous genotype:

48. Two true-breeding stocks of garden peas are crossed. One parent had red, axial flowers, and the other had white, terminal flowers; all F1 individuals had red, axial flowers. If 1,000 F2 offspring resulted from the cross, how many of them would you expect to have red, terminal flowers? (Assume no linkage.)

49. A 9:3:3:1 phenotypic ratio is characteristic of the

50. A 1:2:1 phenotypic ratio in the F2 generation of a monohybrid cross is a sign of

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

52. Roan color in cattle is the result of absence of dominance between red and white color genes. How would one produce a herd of pure-breeding roan-colored cattle?

53. How many different gamete combinations are produced from the genotype Aa?

54. What do all males inherit from their mother?