Consider the following threefactor trihybrid testcross Calcu

Consider the following three-factor (trihybrid) testcross: Calculate the number of expected individuals of A^+a bb C^+C genotype if 1000 progeny result from this testcross.

Solution

A+a X aa ======> 1/2 A+a & 1/2 aa;

B+b X bb ======> 1/2 B+b & 1/2 bb

C+c X cc ======> 1/2 C+c & 1/2 cc

Then proportion of A+abbC+c = 1/2 x 1/2 x 1/2 (Probability multiplication law)

= 1/8

If the total progeny is 1000, then A+abbC+c individuals are

1/8 x 1000 = 125