In Labrador retrievers, two genes determine fur color: the E gene and the B gene. Black fur (B) is dominant to brown fur (b). However, the presence of (ee) will overshadow and create a puppy with yellow fur. Create a Punnett square crossing 2 Labs that are heterozygous for both genes. Then color code your Punnett Square based on the resulting phenotypes. Don't forget to take epistasis into account! Determine the phenotypic ratio.
