What progeny by phenotype and genotype when crossing gray heterosegotic mice of domain color over black ones?

Let’s designate the gene that causes the gray color of the hair of mice as A, then the gene that gives the black hair in the phenotype will be a.

Gray heterozygous mice – Aa, they produce germ cells A and a.

Black mice will be aa, because black coat coloration can only be realized if homozygous. The reproductive cells produced by such mice will be of the same type: a.

All offspring when crossing such mice at the genotype level will look like Aa, which will phenotypically be expressed in the development of gray hair.