Two hypotheses for the assortment of two different genes

This figure shows a cross between two true-breeding pea plants, one with yellow, round seeds and one with green, wrinkled seeds. All the F1 offspring have yellow, round seeds. When the F1 offspring self-fertilize, the two hypotheses predict different phenotypes in the F2 generation. (a) The linkage hypothesis proposes that the two parental alleles always stay associated with each other. In this case, all the F2 offspring will have either yellow, round seeds or green, wrinkled seeds. (b) The independent assortment hypothesis proposes that each allele assorts independently. In this case, the F2 generation will display four different phenotypes. (c) Mendel's observations supported the independent assortment hypothesis.