In minks, the brown color of the fur dominates over the blue. A brown female was crossed with a blue male.

In minks, the brown color of the fur dominates over the blue. A brown female was crossed with a blue male. Among the offspring are two brown and one blue puppies. Is the female purebred?

Let’s designate the gene that causes the brown color of mink fur as C, then the gene that leads to the development of blue fur will be c.

A blue male mink will be cc, since homozygosity is a prerequisite for the realization of this trait. It produces sperm with and can only pass on the blue fur gene to its offspring.

A blue puppy obtained in offspring will also be ss. To be able to produce both brown and blue puppies, the brown female must be heterozygous for the trait in question. Let us write it down, according to the notation, as Сс. It produces two types of eggs: c and C.

Puppies of this pair of individuals with brown fur color are heterozygous – Cc.

Answer: the female mink is not purebred, but heterozygous.