Answer to Question #166986 in Genetics for WADOLE SAHILU

Question

A black guniea pig is crossed albino pig produced 12 offspring with 7 black and 5 albino. what is the best explanation for the situation in punnet square?

Answer 1

It is likely that the allele for black is dominant and the allele for albino is recessive.

Explanation:

It is likely that the allele for black is dominant and the allele for albino is recessive. In the first cross, the parents are both homozygous

Parents: BB & bb (where B is the black allele and b is the white)

The gametes for the black guinea pig are all B, the gametes for the white guinea pig are all b.

All the offspring are heterozygous Bb (see punnet square 1 attached). Because B is dominant, they are all black.

In the second case, where the albino is crossed with another black guinea pig, some albino guinea pigs are born. This suggests that this black guinea pig is heterozygous Bb

The gametes for the albino guinea pig are all b, and the gametes for this black guinea pig are B or b.

This gives a 1:1 ratio of black (Bb) to albino (bb) guinea pigs.