A Map Distance of 23

Question

A map distance of 23.6 between two genes indicates which of the following?
A) The genes are 23.6 millimeters apart.
B) There are 23.6 other genes between the two genes of interest.
C) 23.6% of the offspring exhibit recombination between the two genes.
D) 23.6% of the offspring do not survive.

Accepted Answer

A map distance of 23.6 between two genes indicates that 23.6% of the offspring exhibit recombination between the two genes. This means that there is a 23.6% chance that the genes will be separated from each other during meiosis and that recombinant gametes will be produced. The distance is usually measured in centiMorgans (cM), which is a unit of genetic distance that represents 1% recombination between two genes. Therefore, a map distance of 23.6 cM means that there is a 23.6% chance of recombination between the two genes. Options A, B, and D are not correct because they do not accurately reflect what map distance represents.