You have been given three wrinkled peas, which we shall call  A, B, and C, each of which you plant to produce a mature pea plant. Each of these three plants, once self-pollinated, produces only wrinkled peas.

A. Given that you know that the wrinkled-pea phenotype is recessive, as a result of a loss-of-function mutation, what can you say about the genotype of each plant?

B. How do you determine if each of the three plants carries a mutation in the same gene or in different genes that produce the phenotype?