In chickens, the allele for a pea comb (A) is dominant to the allele for a single comb (a).
A mother with the genotype Aa and a father with the genotype Aa produce an offspring.

What is the percent chance that the offspring will have a single comb?

A. 0%
B. 25%
C. 50%
D. 75%
E. 100%

The correct answer is option B. "25%".

Explanation:

According to Mendel's laws of Inheritance, the genotype of the offspring  from a cross between chickens where the mother has the genotype Aa and the father has the genotype Aa will be 25% AA, 50% Aa and 25% aa. Since the allele for a single comb is recessive, only chickens with a aa genotype will develop a single comb. Therefore, the percent chance that the offspring will have a single comb is equal to 25%.