Black hair in rabbits is determined by a dominant allele, B, and white hair by homozygosity for a recessive allele, b. Two heterozygous rabbits mate and produce a litter of seven offspring. With what frequency would we expect to find:

a) four white and three black offsping

b) one white and six black offspring

Option-B

Explanation:

In the given question,

1. Dominant trait - black, dominant genotype will be - BB or Bb

2. Recessive trait - white, recessive genotype will be - bb

When the cross is performed between the two heterozygous that is between Bb x Bb as follows

B b

B BB Bb

b Bb bb

Since this shows that the dominant allele is expressed by the 3 out of 4 progenies and the recessive allele is expressed by 1 out of 4 progenies. This shows that there is a higher number of rabbits with Black fur than white fur.

Thus from the given question, Option B can be justified with only one white and six black but Option A cannot be justified with three black and fur white.

Thus, Option-B is the correct answer.