Question

What would be the outcome of these crosses between pea plants, where the allele for purple flowers (p) is dominant and the allele for white flowers (p) is recessive at a flower color locus?

Answer 1

Assuming P is purple, p is white. (So purple is dominant over white).

You didn't state the crosses so I will give you some:
1. PPxPP - all PP progeny (purple)
2. pp x pp - all pp progeny (white)
3. PP x pp - all Pp progeny (purple)
I'll put the rest in a picture, because the best way to look at these is via a Punnett Square.