Question

If purple flower color is dominant (P) and red flower color recessive (p), how many phenotypes are possible in offspring of homozygous purple crossed with homozygous red?

Answer 1

As you can see in the cross presented in the image below, all of the offspring of the PP (purple) and pp (red) would all have the heterozygous Pp genotype and have purple flowers, because the P allele is dominant, and only one copy is enough to determine the trait.