Final answer:
When a mouse with white fur is mated with a mouse with grey fur, all the offspring are expected to have grey fur.
Step-by-step explanation:
When a mouse homozygous for white fur (ww) is mated with a mouse homozygous for grey fur (gg), the different types of fur we expect to see in the offspring are determined by the dominant and recessive alleles for fur color. In this case, white fur is recessive (w) and grey fur is dominant (g). So, all the offspring will have grey fur because the dominant allele for grey fur masks the expression of the recessive allele for white fur.