It is found that in cha-cha chickens, the allele for a double 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 produces an offspring.
What is the percent chance that the offspring will have a single comb?
A. 25
B. 100
C. 0
D. 75
E. 50
The genotype of the mother is Aa, which means she has one dominant allele for a double comb (A) and one recessive allele for a single comb (a). The genotype of the father is also Aa, with one dominant allele for a double comb (A) and one recessive allele for a single comb (a).
When the mother and father reproduce, they can produce offspring with the following genotypes:
- AA (double comb)
- Aa (double comb)
- Aa (double comb)
- aa (single comb)
From these possibilities, only one genotype (aa) corresponds to a single comb. Therefore, there is a 1/4 or 25% chance that the offspring will have a single comb.
The answer is A. 25.