In chickens a rose comb (R) is dominant over single comb (r). When a hybrid Rr rose-combed rooster is mated with a single-combed rr hen what combination will be shown in the offspring?

When a hybrid Rr rose-combed rooster is mated with a single-combed rr hen, the possible genotypes of the offspring will be Rr (rose comb) and rr (single comb). This results in a 50% chance of offspring having a rose comb and a 50% chance of having a single comb. Therefore, half of the offspring will display the rose comb phenotype while the other half will show the single comb phenotype.