Egg and Fluffy are two linked bird genes that are 16 map units apart.The E allele of Egg produces large eggs, and the e allele produces small eggs (E is dominant).The F allele produces fluffy feathers, and the f allele produces nonfluffy feathers (F is dominant).If EeFf is crossed with eeff, what proportion of the offspring should be birds that produce small eggs and fluffy feathers? (Note: Assume that the parents of EeFf were EEFF and eeff.)
A) 8 percent
B) 16 percent
C) 42 percent
D) 84 percent
E) 100 percent

Question

Quizplus · Accepted Answer

Given that the Egg and Fluffy genes are 16 map units apart, this indicates a 16% recombination frequency between them. In a cross between EeFf and eeff, the EeFf individual can produce gametes that are recombinant (EF, ef, Ef, eF) with a 16% chance for the recombinant types (Ef and eF) and an 84% chance for the parental types (EF and ef). Since we are looking for offspring that are small eggs and fluffy feathers (ef), we need the eF gamete from the EeFf parent to combine with the e and f from the eeff parent. The eF gamete is a recombinant type, which occurs 16% of the time, but since we're only interested in one of the two recombinant types (eF but not Ef), this halves the probability to 8%.

Egg and Fluffy Are Two Linked Bird Genes That Are