An example of Mendel’s second law. Different genes assort independently into gamete cells. The parental cross (round, yellow seeds x wrinkled, green seeds) yields uniform F1 progeny with the dominant phenotype (round, yellow seeds) and genotype RrYy. The Punnett square analysis assumes random assortment of the different alleles into the gametes formed by the F1 plant. All possible gamete genotypes are written across the top and left side of the grid. The predicted outcome for independent assortment is seeds of four different phenotypes in a 9:3:3:1 ratio, as illustrated below the Punnett square.