In a guinea pig, black body color (A) dominates over white (a), short hair (B)

In a guinea pig, black body color (A) dominates over white (a), short hair (B) over long (b). What genotype will the white shorthaired pig have?

The correct answer is aaBb or aaBb.

Homozygosity is an indispensable condition for the phenotypic realization of a recessive trait, which in this problem indicates the white color of the guinea pig’s coat.

Since short hair, on the contrary, is designated as a trait due to the dominant gene, it will manifest itself in both hetero- and homozygous representation in the animal’s genotype.