Problem

Solutions For An Introduction to Genetic Analysis Chapter 4 Problem 15P

Step-by-Step Solution

Solution 1

The dihybrid cross of two parents E/E F/F and e/e f/f were crossed to get F₁ progeny. The F₁ parent is backcrossed to the recessive parent with the genotype e/e; f/f.

Step #2 of 3

There are four distinct genotypes resulted from the above cross:

EeFf: 25%

Eeff: 25%

eeFf: 25%

eeff: 25%

The phenotypic ratio for the same cross is 1:1:1:1.

Step #3 of 3

In the given progeny, the genotypes are in the following proportions:

• EF – 2/6

• Ef – 1/6

• eF – 1/6

• ef – 2/6

If independent assortment of genes occurs, the ratio of any organism with a homozygous recessive organism would yield the ratio of 1:1:1:1, which is not observed in given question. This is due to linked genes.

The recombinants are eF and Ef and the number of recombinants is 2/6 or 1/3.

Hence, the distance between the two genes would be calculated as: