Two Genes Control Fur Color in Labrador Retrievers

Multiple Choice

Two genes control fur color in Labrador retrievers.The first gene determines whether the pigment to be deposited in the hair will be black or brown.The second gene determines whether the pigments are put into the dog's hair at all.A dog homozygous for the recessive allele of this second gene will be yellow because no pigment is deposited in its fur.This is an example of

A) epistasis.
B) pleiotrophy.
C) codominance.
D) incomplete dominance.