In sweet pea, Lathyrus odoratus, flower color is controlled by two independently assorting gene loci (A, a and B, b).

In sweet pea, Lathyrus odoratus, flower color is controlled by two independently assorting gene loci (A, a and B, b). In order to produce purple-colored flowers a plant must have at least one capital allele at each locus (i.e., must be A_B_ to have purple-colored flowers). Homozygous recessive genotypes for either aa or bb or both result in white-flowered plants. Suppose the following cross is made: AaBb X AaBb. 

(a)