In peas, purple flowers are dominant to white. If a purple-flowered, heterozygous plant were crossed with a white-flowered plant, what is the expected ratio of genotypes and phenotypes among the F1 offspring? If two of the purple-flowered F1 offspring were randomly selected and crossed, what is the expected ratio of genotypes and phenotypes among the F2 offspring?

Verified step by step guidance

1. Identify the genotypes of the parent plants. The purple-flowered parent is heterozygous (Pp) and the white-flowered parent is homozygous recessive (pp).
2. Set up a Punnett square for the F1 generation cross between Pp and pp. The possible gametes from the purple-flowered parent are P and p, and from the white-flowered parent are p and p.
3. Fill in the Punnett square to find the genotypes of the F1 offspring. The resulting genotypes are Pp and pp. Since purple (P) is dominant over white (p), the phenotypic ratio is 1 purple : 1 white.
4. For the F2 generation, cross two purple-flowered F1 offspring (Pp x Pp). Set up a Punnett square with gametes P and p from each parent.
5. Fill in the Punnett square for the F2 generation. The genotypes are PP, Pp, Pp, and pp. The phenotypic ratio is 3 purple : 1 white, and the genotypic ratio is 1 PP : 2 Pp : 1 pp.