Question

White feathers in canaries are dominant to yellow feathers. A heterozygous canary is crossed with a homozygous recessive canary.

What is the ratio of the offspring that are homozygous to the total number of offspring?
:


What percent of the offspring will be heterozygous?
%
A Punnett square is shown. The columns are labeled Upper A and a to represent the white canary. The rows are labeled a and a to represent the yellow canary. Clockwise from uppercase left the boxes contain: 1, 2, 4, 3.

Answer 1

Cross: Aa × aa

Offspring genotypes: 50% Aa (heterozygous) and 50% aa (homozygous recessive).

- Ratio of homozygous to total = 1/2 (50%).
- Percent heterozygous = 50%.