Question

Recall Mendel's pea plants:the allele for purple flowers, P, is dominant to the allele for white flowers, p. Avery large number of offspring from a cross of two plants are observed. If ALL of those offspring have purple flowers, what are the possible genotypes of the parents in the cross?

Answer 1

Answer:

PP x PP; PP x Pp; PP x pp

Explanation:

Since the allele for purple flowers, P, is dominant, in order to be possible for all the offspring to have purple flowers, at least one of the parents must have the homozygous dominant genotype PP.

If one of the parents has a homozygous dominant genotype, all of the offspring will have purple flowers regardless of the other parent's genotype since one allele P will be passed down. Therefore, all of the possible genotype combinations are:

PP x PP; PP x Pp; PP x pp