A double heterozygote for two linked genes in the mouse is test-crossed by crossing it to a homozygous recessive parent. In the offspring, the two parental classes appear in a frequency of 45% each, and the two recombinant classes appear in a frequency of 5% each. What is the distance in map units between the two genes?
A) 45 m.u.
B) 22.5 m.u.
C) 10 m.u.
D) 5 m.u.
E) 2.5 m.u.

Question

Quizplus · Accepted Answer

The distance between two genes is calculated as the percentage of recombinant offspring. In this case, the recombinant offspring appear in a frequency of 5% each, so the distance between the two genes is 5 m.u.

A Double Heterozygote for Two Linked Genes in the Mouse