: Remembering that cells in the epidermis get all their nutrients via diffusion from the blood vessels in the dermis, why would it be useful for the connection between the two layers to have more surface area?

In the mouse, gene a allows pigmentation to be deposited in the individual coat hairs; its allele a prevents such deposition of pigment, resulting in an albino. gene b gives agouti (wild-type fur); its allele b gives black fur. what would the expected ratio of the progeny be in a cross of a doubly heterozygous agouti mouse mated with a doubly homozygous recessive white mouse? 1 (agouti) : 1 (black) : 1 (albino) 9 (agouti) : 3 (black) : 4 (albino) 3 (agouti) : 4 (black) : 9 (albino) 1 (agouti) : 1 (black) : 2 (albino) 9 (black) : 27(albino)