A black guinea pig crossed with an albino guinea pig produced twelve black offspring. When the albino was crossed with a second black animal, six blacks and six albinos were obtained. What is the best explanation for this genetic situation?

Question

Quizplus · Accepted Answer

The fact that the first cross between a black guinea pig and an albino guinea pig produced only black offspring suggests that black is the dominant trait and albino is recessive. This is further supported by the second cross between the albino guinea pig and a black animal, which produced both black and albino offspring in a 1:1 ratio, indicating that the black parent was heterozygous for the black trait (Bb) and the albino parent was homozygous recessive (bb). Therefore, the best explanation for this genetic situation is that albino is recessive and black is dominant.

A Black Guinea Pig Crossed with an Albino Guinea Pig