In fruit flies,bar eye is inherited by an X-linked allele (B for bar).If a heterozygous bar-eyed female is mated to a non-bar-eyed male,what will be the expected ratio of phenotype given four offspring?
A)two bar-eyed females,two bar-eyed males
B)one bar-eyed and one non-bar-eyed female,one bar-eyed and one non-bar-eyed male
C)three bar-eyed females and one non-bar-eyed male
D)bar-eyed females only
E)non-bar-eyed males only

Question

Quizplus · Accepted Answer

The heterozygous female has one X chromosome with the bar allele and one X chromosome with the non-bar allele. The non-bar-eyed male has two non-bar alleles. Therefore, the possible genotypes of the offspring are BB, B, and non-bar. The expected ratio of phenotypes in four offspring would be one of each of the possible genotypes, resulting in one bar-eyed and one non-bar-eyed female, one bar-eyed and one non-bar-eyed male.

In Fruit Flies,bar Eye Is Inherited by an X-Linked Allele