Answer to Question #137214 in Genetics for Rikeya

Question

In cats, black coat color is dominant over gray. A female black cat whose mother is gray mates with a gray male. If this female has a litter of kittens, what is the probability that the mating will produce gray kittens? Show your work in a Punnett square and give the probability.

Answer 1

Because black (B) is dominant over gray (d), a black cat may be homozygous (BB) or heterozygous (dd). The black female in this problem must be heterozygous (Bd) because her mother is gray (dd) and she must inherit one of her mother alleles. The gray male is homozygous (dd) because gray is recessive. Thus the cross is:

BB dd black female gray male Dd black Bb gray.

The probability of obtaining gray kittens is

$\frac{8}{16}$.

=$\frac{1} {2}$