Problem

Solutions For An Introduction to Genetic Analysis Chapter 5 Problem 26P

Step-by-Step Solution

Solution 1

The gene order of two E. coli strains is as below:

a. The gene order is determined by comparing arg⁺ bio⁺leu‾ with arg⁺bio‾ leu⁺. If the gene order is arg leu bio, four crossovers would be required to get arg⁺ leu‾ bio, whereas only two crossovers would be required to get arg leu⁺ bio‾. If the gene order is arg bio leu, four crossovers would be required to get arg⁺ bio⁺ leu‾. There are eight recombinants that are arg⁺ bio⁺ leu‾ and none that are arg⁺bio‾ leu⁺. The gene order is arg bio leu on the basis of the frequencies of these two classes.

Step #2 of 3

The map distances in recombination percentages are:

b. The arg-bio map distance is determined by calculating the percentage of the exconjugants that are arg⁺ bio‾ leu‾. Between the arg and bio genes these cells would have had a crossing over event. A recombinant frequency can be calculated as follows: