Question

A dog breeder has a brown-haired dog (Bb) and a white-haired dog (bb). If she breeds these dogs, and the mother has a litter of 8 pups, how many should have white fur?

Answer 1

4

Step-by-step explanation:

The mother dog has the genotype (bb), which means she can only pass on the recessive white fur allele (b) to her offspring. The father dog has the genotype (Bb), and he can pass on either the dominant brown fur allele (B) or the recessive white fur allele (b).

When they breed, each of the 8 pups has a 50% chance of inheriting the brown allele (B) and a 50% chance of inheriting the white allele (b) from the father.

So, on average, 4 of the 8 pups should inherit the white fur allele (bb) from the father, and therefore, 4 pups should have white fur.