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?

Explanation:

Step1: Determine the genotypes of the parents

The heterozygous canary has the genotype \(Aa\), and the homozygous recessive canary has the genotype \(aa\).

Step2: Analyze the Punnett square

The Punnett square for the cross \(Aa\times aa\) gives the following offspring genotypes: \(Aa\), \(aa\), \(Aa\), \(aa\).

Step3: Calculate the ratio of homozygous offspring

There are 2 homozygous (\(aa\)) offspring out of 4 total offspring. The ratio is \(\frac{2}{4}=\frac{1}{2}\).

Step4: Calculate the percentage of heterozygous offspring

There are 2 heterozygous (\(Aa\)) offspring out of 4 total offspring. The percentage is \(\frac{2}{4}\times100\% = 50\%\).

Answer:

The ratio of homozygous offspring to the total number of offspring is \(1:2\). The percentage of heterozygous offspring is \(50\%\).