75% rose comb 25% single comb

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

given,

rose combed rooster (R) * single combed hen (r)

RR * rr

↓

in F1 generation, all the chicks will be Rr

↓

in F2 generation, mating was done among their own group of Rr

Rr * Rr

↓

25% of RR 50% of Rr and 25% of rr

phenotypes of chicks in f2 generation = 3:1 (75% rose combed as R is dominant and 25% single combed)

genotype = 1:2:1 (1/4 homozygous rose comb [RR] : 2/4 heterozygous rose comb [Rr] : 1/4 homozygous single comb [rr])