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.

表2listsPisum sativumgenotypes and the phenotype associated with each genotype.

Table 3 lists 6Pisum sativumcrosses, 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.