Chapter 12 Back of the Book Questions

In a cross of Aa Bb cc X Aa Bb Cc, what is the probability of obtaining an individual with the genotype AA Bb Cc? a. 1/16 c. 1/64 b. 3/16 d. 3/64

A. 1/16

What is the probability of obtaining an individual with the genotype bb from a cross between two individuals with the genotype Bb? a. 1⁄2 c. 1/8 b. 1⁄4 d. 0

B. 1/4

What property distinguished Mendel's investigation from previous studies? a. Mendel used true-breeding pea plants. b. Mendel quantified his results c. Mendel examined many different traits. d. Mendel examined the segregation of traits.

B. Mendel quantified his results

An organism's ______ is/are determined by its _________. a. genotype; phenotype b. phenotype; genotype c. alleles; phenotype d. genes; alleles

B. phenotype; genotype

The F1 plants from the previous question are allowed to self- fertilize. The phenotypic ratio for the F2 should be a. all purple. c. 3 purple:1 white. b. 1 purple:1 white. d. 3 white:1 purple.

C. 3 purple: 1 white

The F1 generation of the monohybrid cross purple (PP) × white (pp) flower pea plants should a. all have white flowers. b. all have a light purple or blended appearance. c. all have purple flowers. d. have 3⁄4 purple flowers, and 1⁄4 white flowers.

C. All have purple flowers

When you cross true-breeding tall and short tobacco plants you get an F1 that is intermediate in height. When this F1 is self-crossed, it yields an F2 with a continuous distribution of heights. What is the best explanation for these data? a. Height is determined by a single gene with incomplete dominance. b. Height is determined by a single gene with many alleles. c. Height is determined by the additive effects of many genes. d. Height is determined by epistatic genes.

C. Height is determined by the additive effects of many genes

Which of the following is NOT a part of Mendel's five-element model? a. Traits have alternative forms (what we now call alleles). b. Parents transmit discrete traits to their offspring. c. If an allele is present it will be expressed. d. Traits do not blend.

C. If an allele is present it will be expressed

If the two genes in the previous question showed complete linkage, what would you predict for an F2 phenotypic ratio? A. 1 red tall:2 pink short:1 white short B. 1 red tall:2 red short:1 white short C. 1 pink tall:2 red tall:1 white short D. 1 red tall:2 pink tall:1 white short

D. 1 red tall: 2 pink tall: 1 white short

Japanese four o'clocks that are red and tall are crossed to white short ones, producing an F1 that is pink and tall. If these genes assort independently, and the F1 is self-crossed, what would you predict for the ratio of F2 phenotypes? a. 3 red tall:1 white short b. 1 red tall:2 pink short:1 white short c. 3 pink tall:6 red tall:3 white tall:1 pink short:2 red short:1 white short d. 3 red tall:6 pink tall:3 white tall:1 red short:2 pink short:1 white short

D. 3 red tall: 6 pink tall: 3 white tall: 1 red short: 2 pink short: 1 white short

endel's model assumes that each trait is determined by a single factor with alternate forms. We now know that this is too simplistic and that a. a single gene may affect more than one trait. b. a single trait may be affected by more than one gene. c. a single gene always affects only one trait, but traits may be affected by more than one gene. d. a single gene can affect more than one trait, and traits may be affected by more than one gene.

D. a single gene can affect more than one trait, and traits may be affected by more than one gene

Phenotypes like height in humans, which show a continuous distribution, are usually the result of a. an alteration of dominance for multiple alleles of a single gene. b. the presence of multiple alleles for a single gene. c. the action of one gene on multiple phenotypes. d. the action of multiple genes on a single phenotype.

D. the action of multiple genes on a single phenotype