Answer
(a) Recombination frequencies are made by crossing homozygous recessive (for both genes) individuals with heterozygous individuals and looking for recombinant phenotypes (this is basically a test cross for 2 genes at once). The percentage of recombinants gives the recombination frequency and the map distance.
(b) Please see the image for the map.
![](https://gradesaver.s3.amazonaws.com/uploads/solution/b87ebc12-e8f9-45fb-8c3b-8b73ea4e1c23/result_image/1475273139.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAJVAXHCSURVZEX5QQ%2F20240727%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240727T021949Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=846ec5bffc206b5d479e75984d85e8ee339a1f07f5a4eb3a92deb9486a024b55)
Work Step by Step
The map is produced by playing with the various pairwise distances until an overall map is found which fits them all--it's like doing a puzzle in which the pieces vary by length, using trial-and-error.