Essential Genetics 6th Edition by Daniel Hartl

تمرين 5

A cell undergoing meiosis in an organism with unordered tetrads undergoes a double crossover between two markers. If the ratio of 2-strand : 3-strand : 4-strand doubles is 1 : 2 : 1, what is the ratio of PD : TT : NPD tetrads? (PD stands for parental ditype tetrad, TT for tetratype, and NPD for nonparental ditype.)