Biology Chapter 12 Review 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?

1/64

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?

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

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?

Height is determined by the additive effects of many genes.

The F1 generation of the monohybrid cross purple (PP) × white (pp) flower pea plants should

Mendel quantified his results.

The F1 plants from the previous question are allowed to selffertilize. The phenotypic ratio for the F2 should be

all have purple flowers

An organism's is/are ____________ determined by its____________.

phenotype; genotype

Phenotypes like height in humans, which show a continuous distribution, are usually the result of

the action of multiple genes on a single phenotype

Which of the following is NOT a part of Mendel's five-element model?

3 purple:1 white.

What is the probability of obtaining an individual with the genotype bb from a cross between two individuals with the genotype Bb?

0

If the two genes in the previous question showed complete linkage, what would you predict for an F2 phenotypic ratio?

1 red tall:2 pink tall:1 white short

What property distinguished Mendel's investigation from previous studies?

Mendel quantified his results.

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