In Drosophila melanogaster, the allele for red eyes is dominant over the allele for purple eyes, and the allele for a gray body is dominant over the allele for a black body. A testcross was done to check for genetic linkage between the genes for these traits. The results for the offspring are listed below:
478 flies with red eyes and a gray body
27 flies with red eyes and a black body
462 flies with purple eyes and a black body
33 flies with purple eyes and a gray body
Which of the choices below best represents the map distance between the genes for these two traits?

Question

Quizplus · Accepted Answer

The map distance is calculated using the formula: (Number of recombinant offspring / Total number of offspring) x 100. The recombinant offspring are those with red eyes and black body (27) and purple eyes and gray body (33), totaling 60. The total number of offspring is 1000. Thus, the map distance is (60/1000) x 100 = 6.0 map units.

In Drosophila Melanogaster, the Allele for Red Eyes Is Dominant