Essential Genetics 6th Edition by Daniel Hartl

Exercise 2

The yeast Saccharomyces cerevisiae has unordered tetrads. In a cross carried out to study the linkage relationships among three genes, the tetrads in the accompanying table were obtained. The cross was between a strain of genotype + b c and one of genotype a + +.
(a) From these data determine which, if any, of the genes are linked.
(b) For any linked genes, determine the map distances.