1 The allele for white hair in mice is autosomal recessive b

1. The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white female mouse mates with a black male mouse. What are the possible genotypes for the white female mouse?

2. The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white female mouse mates with a black male mouse. If the offspring are half black and half white, what are the possible genotypes for the black male mouse?

Solution

1. The possible genotype for the white female mouse is bb.

2. The possible genotype for the black male mouse is Bb if the offspring are half black and half white.

In I case, bb X Bb will give following genotypes:

Bb(black male), bb(white female), Bb(black male) and bb(white female)

so the possible genotype for the white female mouse is bb

If the offspring are half black and half white, what are the possible genotypes for the black male mouse?

hence, they are talking about a cross between bb and Bb. Because only this cross will result in half black and half white offspring.(white females bb and black males Bb).

A cross between bb and BB will result in only one type of affected offspring Bb.