1. In a certain breed of domestic fowl, pea comb is dominant to single comb but feather colour shows absence of dominance. Black feathers and white feathers are homozygous, whereas the heterozygote gives blue feathers. From crosses between birds heterozygous for both genes, what proportion of the offspring would you expect to be: (Define the alleles and show all your work.)
a. Pea-combed
b. Black-feathered
c. Blue-feathered
d. Pea-combed and blue-feathered
e. Single-combed and white-feathered