Question: Consider the following hypothetical scheme of determination of coat color in a mammal. Gene A con…

Consider the following hypothetical scheme of determination of
coat color in a mammal. Gene A controls the conversion of a white
pigment P0 into a gray pigment P1 the dominant allele A produces
the enzyme necessary for this conversion, and the recessive allele
a produces an enzyme without biochemical activity. Gene B controls
the conversion of the gray pigment P1 into a black pigment P2; the
dominant allele B produces the active enzyme for this conversion,
and the recessive allele b produces an enzyme without activity. The
dominant allele C of a third gene produces a polypeptide that
completely inhibits the activity of the enzyme produced by gene A ;
that is, it prevents the reaction P0➝P1. Allele c of this gene
produces a defective polypeptide that does not inhibit the reaction
P0➝P1. Genes A, B, and C assort independently, and no other genes
are involved. In the F2 of the cross AA bb CC x aa BB cc , what is
the expected phenotypic segregation ratio?