You are mapping the location of two genes in Drosophila, listless l and blind b. (l+ l+ b+ b+) and (l+ l- b+ b-) flies are normal, but ( l- l- b- b-) flies don't move around very much and cannot detect the location of a light source. You perform a testcross and get the following results: listless, sighted 100 listless, blind 400 normal activity, sighted 400 normal activity, blind 100 What is the distance between these two genes on the chromosome?

Question

Quizplus · Accepted Answer

The recombinant offspring (listless, sighted and normal activity, blind) total 200 (100 + 100). The total number of offspring is 1000 (100 + 400 + 400 + 100). The recombination frequency is 200/1000 = 0.2, which corresponds to 20 map units apart.

You Are Mapping the Location of Two Genes in Drosophila