Question

In field mice, brown fur is dominant and white fur is recessive. If a field mouse that is heterozygous for brown fur breeds with a field mouse that is homozygous for white fur, what is the probability that their offspring will have white fur?
75%
25%
100%
50%

Answer 1

let B be the dominant allele for fur color and b be the recessive

Heterozygous brown = Bb
Homozygous recessive = bb

Punnett square:



complete the punnet square by filling in the appropriate allele from each parent, then see what % of the offspring are homozygous recessive (white fur)