I was asked this question on a test and got it wrong, but I'd like to know how to do it. The answers are shown in the blanks below:
You are studying two recessive mutations in the fruit fly D. melanogaster. The red_ mutation causes flies to have red bristles (wild-type flies have black bristles) and the shiny- mutation causes flies to have shiny eyes (wild-type flies have eyes that are pebbly). You mate females from a true-breeding strain with red bristles and pebbly (wild-type) eyes to males from a true-breeding strain with black (wild-type) bristles and shiny eyes. F1 females are then mated to males that have red bristles and shiny eyes to produce F2 progeny.
If you analyzed 1000 male progeny in the F2 generation, how many flies of each possible phenotypic class would you expect, if:
The two traits are determined by two autosomal genes that are 15 cM apart:
Red bristles, pebbly eyes:_____ 425_______ Red bristles, shiny eyes: ______75____ Black bristles, pebbly eyes:____ 75_____ Black bristles, shiny eyes:____ 425______
So I know the 15cm=recombinants/parentals * 100 but I don't see how that formula can help.