In Drosophila Melanogaster, Vestigial Wings Are Determined by a Recessive

Multiple Choice

In Drosophila melanogaster, vestigial wings are determined by a recessive allele of a gene that is linked to a gene with a recessive allele that determines black body color. T. H. Morgan crossed black-bodied, normal-winged females and gray-bodied, vestigial-winged males. The F₁ were all gray bodied, normal winged. The F₁ females were crossed to homozygous recessive males to produce testcross progeny. Morgan calculated the map distance to be 17 map units. Which of the following information is correct about the testcross progeny?

A) black-bodied, normal-winged flies = 17% of the total
B) black-bodied, normal-winged flies plus gray-bodied, vestigial-winged flies = 17% of the total
C) gray-bodied, normal-winged flies plus black-bodied, vestigial-winged flies = 17% of the total
D) black-bodied, vestigial-winged flies = 17% of the total