Question

The 1860s Gregor Mendel performed numerous dihybrid crosses between pea plants. Dihybrid

crosses involve the study of the inheritance patterns related to two different traits. 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? B
F 0%
G 25%
H 50%
J 100%

Answer 1

Answer: The percentage of the offsprings from the cross that will be heterozygous for both trait is 25%

Explanation: A dibybrid cross between two guinea pigs of genotype BbFf and bbff will produce 16 offsprings. The genotype ratio of the offsprings is 4 BbFf : 4 Bbff: 4 bbFf : 4 bbff.

Only 4 BbFf offsprings are heterozygous for both trait therefore the percentage of the offsprings that are heterozygous for both trait is (4/16) x 100 = 25%

See the punnett square attached for details of the dibybrid cross