1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) are all found on the X-chromosome of Drosophila melanogaster. All of these are recessive traits. They map in the order rb, ct, t with 12.5 map units between rb and ct and 7.5 map units between ct and t. Suppose you cross a cut wing male with a homozygous female that is both tan and has ruby eyes.
a. What will the F1 females look like?
b. Draw map of the section of the X chromosomes that has these 3 genes for the F1 females
c. Assume you testcross your F1 females.
i. What progeny classes would you expect?
ii. Give approximate numbers for each class based on a total of 2000 progeny.
1. Assuming the i=1 and there are no double crossovers.
2. Assuming the i=0 and there are the expected number of double crossovers.