Question

In mice with black agouti coats, each hair is black and yellow. Two mice with black agouti coats are crossed. Among the offspring, most of the mice have black agouti coats, and the rest of the mice have nonagouti coats with solid black hairs.Based on the results of the cross, which of the following statements describes the most likely genetics of the coat color in the mice?

A The agouti allele is recessive to the nonagouti allele.
B The agouti allele is dominant to the nonagouti allele.
C The agouti allele and nonagouti allele are sexlinked.
D The agouti allele and nonagouti allele are codominant.

Answer 1

A, the agouti allele is recessive to the nonagouti allele. Since both of the sex partners had the black agouti coats then if the gene had been dominant the black agouti coats should have been across all of the offpsring. But it seems that over time it could slowly deteriorate.