Question

An individual with genotype AA is crossed to an individual with genotype aa at the same genetic locus. The allele A is dominant to the allele a. If the offspring are interbred through two generations, what is the predicted ratio of phenotypes in the F2 generation?

Answer 1

The complete question is:

An individual with genotype AA is crossed to an individual with genotype aa at the same genetic locus. The allele A is dominant to the allele a.

If the offspring are interbred through two generations, what is the predicted ratio of phenotypes in the F2 generation?

9:16 (dominant:recessive)

9:7 (dominant:recessive)

3:16 (dominant:recessive)

1:3 (dominant:recessive)

Answer:

3:1 dominant:recessive phenotype ratios

Explanation:

The recessive phenotype disappears in the F1 generation, but it reappears in the F2 at a ratio of 3:1, being therefore dominant:recessive