QUIZ 16

d. 50%

A man is heterozygous for the hemoglobin gene, with one normal allele and one sickle allele. What are the chances that one of his sperm cells will have the sickle allele for hemoglobin? a. 100% b. 75% c. 25% e 0% d. 50%

c. 100% Rr genotype, and 100% round-pea phenotype

Assume Mendelian genetics for this question. For a cross of dominant round-pea plants (R) to recessive wrinkled-pea plants (r), the F1 generation will be a. 75% round-pea phenotype b. 100% RR genotype, and 100% round-pea phenotype c. 100% Rr genotype, and 100% round-pea phenotype d. 100% rr genotype, and 100% wrinkled-pea phenotype e. 100% Rr genotype, and 50% round-pea phenotype

e. all Tt

Assume Mendelian inheritance for this question. If you cross a tall plant with homozygous dominant genotype TT to a short plant with homozygous recessive genotype tt, the offspring of that cross would have the genotype ratio of a. 3 TT: 1 tt b. 1 TT: 3 tt c. all TT d. 1 TT: 2 Tt: 1 tt e. all Tt

c. only type O or type A

Blood type shows co-dominance, and has multiple alleles, i, IA and IB. A mother with blood genotype ii and a father with blood genotype iIA have children. What are the possible blood phenotypes of the children? a. only type O or type B b. only type B c. only type O or type A d. only type O e. only type O, type A, or type B

c. gg

Green pod color (G) is dominant to yellow pod color (g). Which of the following genotypes could be for a plant with yellow pods? a. gg or GG b. Gg or GG c. gg d. Gg e. GG

a. shows incomplete dominance.

Having LDL receptors (H) is dominant to not having LDL receptors (h). You cross HH mice to hh mice, then breed their offspring to each other to create an F2 generation. In the F2 generation you see 97 mice with no disease, 208 mice with mild disease, and 105 mice with severe disease. This result indicates that the gene for LDL receptors a. shows incomplete dominance. b. shows codominance. c. is polygenic. d. is a Mendelian characteristic. e. makes a protein that causes a phenotype that is sensitive to the environment.

e. pleiotropic.

If many characteristics are affected by one gene, the gene is a. polygenic. b. an example of incomplete dominance. c. an example of multiple alleles. d. Mendelian. e. pleiotropic.

d. all green-pod plants

Imagine a monohybrid cross studying pod color. The green phenotype (G) is dominant and the yellow phenotype (g) is recessive. The phenotype ratio of the plants of the F1 generation would be a. all yellow-pod plants b. 3 green-pod plants : 1 yellow-pod plant c. 1 green-pod plant : 1 yellow-pod plant d. all green-pod plants e. 1 green-pod plant : 2 constricted-pod plants : 1 yellow-pod plant

c. 250

In a Mendelian monohybrid cross of a pea plant with dominant tall (T) plants with a plant with recessive short (t) plants, how many offspring of 1000 plants in the F2 generation would you predict will be homozygous dominant? a. 1000 b. 750 c. 250 d. none e. 500

d. He controlled which plants bred using monohybrid crosses and counted the traits of many offspring.

Mendel studied inheritance before anyone knew about DNA, mitosis or meiosis. What experiments did he do? a. He let many plants breed randomly with each other and made careful observations of the probability of each trait appearing in the entire population. b. He crossed two plants that were heterozygous (hybrid) for one of seven characters in the parental generation. c. He watched the formation of gametes under a microscope and inferred the main elements of meiosis and properties of DNA. d. He controlled which plants bred using monohybrid crosses and counted the traits of many offspring. e. He stored pollen from plants so once the structure of DNA was understood in the 1950's the traits that were present in the mid 1800's could be studied.

c. type B

Mom has type A blood. She has two children with Dad. One child has type AB blood and the other child has type O blood. What type of blood does Dad have? a. type O b. type AB c. type B d. Dad's blood type cannot be determined from the information given. e. type A

b. polygenic inheritance.

Not all phenotypes are inherited in a Mendelian fashion. For example, many genes affect human skin color. The fact that human skin color is determined by many genes is an example of a. incomplete dominance. b. polygenic inheritance. c. codominance. d. pleiotropy. e. multiple alleles.

a. 3 tall plants : 1 short plant

Plant height is Mendelian. Tall plants are dominant to short plants. In a monohybrid cross of a tall plant to a short plant, the F2 generation would have a phenotype ratio of a. 3 tall plants : 1 short plant b. all short plants c. all tall plants d. 1 short plant : 2 medium-height plants : 1 short plant e. 3 short plants : 1 tall plant

d. 1 red: 2 pink: 1 white

Red flowers show incomplete dominance. If you cross a P generation of plants with red flowers (RR) and white flowers (rr), what phenotypic ratio of flower color would you predict in the F2 generation? a. 1 pink: 3 white b. 2 red: 1 pink: 1 white c. all pink d. 1 red: 2 pink: 1 white e. 3 red: 1 white

b. They would be the same; both would be 1:2:1.

Red flowers show incomplete dominance. If you cross a P generation of plants with red flowers (RR) and white flowers (rr), what would you predict about the phenotype and genotype of the F2 generation? a. They would be the same; both would be 3:1. b. They would be the same; both would be 1:2:1. c. They would be different. The phenotype ratio would be 3:1, and the genotype ratio would be 1:2:1. d. They would be the same. The phenotype ratio would be all red, and the genotypes would be all Rr. e. They would be different. The phenotype ratio would be 1:2:1, and the genotype ratio would be 3:1.