Mendel crossed peas having green seeds with peas having yellow seeds. The F₁ generation produced only yellow seeds. In the F₂, the progeny consisted of 6022 plants with yellow seeds and 2001 plants with green seeds. Of the F₂ yellow-seeded plants, 519 were self-fertilized with the following results: 166 bred true for yellow and 353 produced an F₃ ratio of 3/4 yellow: 1/4 green. Explain these results by diagramming the crosses.