In drosophila, a cross was made between a yellow- bodied male with vestigial (not fully developed) wings and a wild-type female (brown body). the f1 generation consisted of wild-type males and wild-type females. f1 males and females were crossed, and the f2 progeny consisted of 16 yellow-bodied males with vestigial wings, 48 yellow-bodied males with normal wings, 15 males with brown bodies and vestigial wings, 49 wild-type males, 31 brown-bodied females with vestigial wings, and 97 wild-type females. explain the inheritance of the two genes in question based on these results.

The body color gene is sex-linked and the vestigial gene is autosomal.

Explanation:

1st cross)  yellow-bodied male with vestigial wings X wild-type female (brown body)

F1: wild-type males and females

2nd cross) F1 x F1

F2:

16 yellow-bodied males with vestigial wings

48 yellow-bodied males with normal wings

15 males with brown bodies and vestigial wings

49 wild-type males

31 brown-bodied females with vestigial wings

97 wild-type females

Total: 256

Let's analyze the traits (body color and wings) one at a time:

Wing shape

These proportions are similar to 1/4 vestigial, 3/4 normal wings. In addition, males and females have the same amount of individuals with vestigial wings. This suggests that the wing shape gene is autosomal, with the allele vg+ being wild-type and dominant over the vestigial vg allele..

Body color

The ratios are also 1 yellow : 3 brown, but there's a difference between males and females. This suggests that the gene that determines body color is sex-linked.

With this hypothesis, let's do the crosses considering the genotypes:

1) Parents: XʸY vg vg X Xʸ⁺Xʸ⁺ vg+ vg+

F1:  Xʸ⁺Y vg vg+ and Xʸ⁺Xʸ vg vg+  (all wild-type)

2) F1xF1 gives us the offspring predicted in the Punnett Square, which matches the proportions observed in the F2.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.