Question

In chickens, rose comb (R) is dominant to single comb (r). A homozygous rose-combed rooster is mated with a single-combed hen. All of the chicks in the F1 generation were kept together as a group for several years. They were allowed to mate only within their own group. What is the expected phenotype of the F2 chicks?

Answer 1

Answer:

25% Homozygous Rose Comb, 25% Homozygous Single Comb and 50% Heterozygous Rose Comb.

Explanation:

For a homozygous rose combed rooster (RR) and a homozygous single combed hen (rr), their first offspring F1 will be 100% heterozygous rose combed which has the genotype of Rr.

If the F1 generation are allowed to mate only among themselves, the second generation offspring, F2, will have 3 different genotypes which are homozygous rose comb (RR), homozygous single comb (rr) and heterozygous rose comb (Rr).

I hope this answer helps.