Question

In guinea pigs the allele for black fur (B) is dominant over the allele for brown fur (b), and the allele for short fur (F) is dominant over the allele for long fur (f). What percentage of the offspring from a BBFF x bbff cross would be expected to be heterozygous for both traits?

Answer 1

Answer:

100%

Explanation:

This question involves two genes in guinea pigs; one coding for fur color and the other for fur length. The alleles of black fur (B) and short fur (F) is dominant over the alleles for brown fur (b) and long fur (f).

In a cross between two offsprings with genotypes: BBFF x bbff, the following gametes will be produced by each parent:

BBFF - BF, BF, BF, and BF

bbff - bf, bf, bf, bf

Using these gametes in a punnet square (see attached image), one will notice that all of the offsprings will have the genotype: BbFf i.e all or 100% of the offsprings are heterozygous for both of the genes or traits.