Question

Phenotypically wild-type F1 female Drosophila, whose mothers had light eyes (lt) and fathers had straw (stw)

bristles, produced the following offspring when crossed to homozygous light-straw males:
Phenotype Number
light-straw 22
wild-type 18
light 970
straw 970
Total: 2000
Compute the map distance between the light and straw loci.
A) 4 map units B) 98 map units C) 12 map units D) 8 map units E) 2 map units

Answer 1

The map distance between the light and straw loci is approximately 1.1%.

Step-by-step explanation:

The map distance between the light and straw loci can be calculated using the formula:

Map distance = (number of recombinant offspring / total number of offspring) x 100

In the given question, the phenotype ratios provide the number of recombinant offspring: light-straw (22) and wild-type (18). The total number of offspring is 2000. Plugging these values into the formula:

Map distance = (22 / 2000) x 100 = 1.1%

Therefore, the map distance between the light and straw loci is approximately 1.1%.