Question

You are given two populations of true-breeding tomato plants with two simple dominant/recessive traits that sort independently. Using the multiplication rule, how many different phenotypic combinations would you expect to see in the F2 generation?

Answer 1

We would see four different phenotypic combinations with the ratio 9:3:3:1.

A cross in which two traits are studied at a time is termed as a dihybrid cross. As a result of dihybrid cross, 16 genotypic probabilities can be formed in different ratios depending on the type of the parents. The phenotypic ratio of a dihybrid cross between parents who are true breeding for the dominant and the recessive allele would be 9:3:3:1.