Comb shape in chickens is determined by 2 different genes that independently assort (R/r and P/p). A walnut comb is produced with at least one "R" allele and one "P" allele. A rose comb is produced with at least one "R" allele and two "p" alleles. A pea comb is produced by two "r" alleles and at least one "P" allele. A single comb is produced when both genes are homozygous recessive. If a single comb chicken is mated with a pea comb chicken that is homozygous for the "P" allele, what phenotype(s) for comb is/are expected in their offspring?
a) Only pea comb
b) Only single comb
c) 1/2 pea comb and 1/2 single comb
d) 3/4 pea comb and 1/4 single comb
Ans: a) Only pea comb
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