Question

A cross was done using pairs of mice.One parent was a mouse with white (bb).The other parent was a mouse with black fur.Some of the offspring produced from this cross had white fur. What genotype did this parent with black fur have in order to produce some offspring with white fur.

Answer 1

Bb
because both parents should have the recessive allele in order to have some of the offsprings being white furred.
in this case the first parent had (bb) thus the second had (Bb) because it had black fur but still had some white furred babies and some black furred babies

Answer 2

The parent with black fur had genotype Bb.

Step-by-step explanation:

White fur is recessive in mice, so a mouse with white fur has to have two alleles of the white fur gene (bb). Black fur is dominant to white fur, so a mouse with black fur only needs one allele of the black fur gene (BB or Bb). In order for a black mouse and a white mouse to produce white offspring, the black parent has to have an allele for the white fur gene (Bb).