A Series of Crosses to Test Whether Two Genes in Drosophila

question 5

Essay

A series of crosses to test whether two genes in Drosophila flies are sex-linked and on the same chromosome, and which alleles are dominant, are described below. Match each conclusion with the piece of evidence supporting it.
A cross between a true-breeding black, apterous (no wings) female parent and a true-breeding wild-type male parent produced 100% F₁ offspring with wild-type phenotype in both sexes. A test cross of an F₁ male with the female parent produced 45% wild-type flies, 45% black, apterous flies, 5% flies with a black body and normal wings, and 5% apterous flies with a normal colored body.
a. The two genes are autosomal
b. Normal wings is dominant
c. The two genes are on the same chromosome