Question

Guinea pig coat color is determined by a single gene. The allele for black coat color is dominant to brown. In a cross between two black-haired guinea pigs, 20 offspring are born. If both parents were heterozygous, probability would predict that approximately how many of the 20 offspring would have brown hair?

Answer 1

1/4 offsprings are going to have brown hair so, 5 offsprings will have brown hair out of 20

Answer 2

Answer: 5

The representation of the genotypes of heterozygous parents with dominant black coat is: Bb

In F1 generation by the cross of parents, the type of hair colour of the offspring can be predicted by punnet squares.

Offspring that are homozygous dominant (bb): 1 out of 4 or 1/4=25%

For 20 offsprings, the number of offsprings with brown hair=( ¼)20= 5