Gregor Mendel discovered the basic principle of independent assortment in genetics through selective cross-breeding of common pea plants (Pisum sativum). Table 1 lists the possible alleles of 4 of the genes Mendel discovered, and the possible genotypes for each.

Table 2 lists Pisum sativum genotypes and the phenotype associated with each genotype.

Table 3 lists 6 Pisum sativum crosses, the genotypes of each parent, and the percentage of offspring that displayed each phenotype for the traits listed in Table 2. Multiple matings of each genotype pairing were performed.