Question

1) Which cross would produce purple and white flowers in the offspring if purple flowers (P) are dominant to white flowers (p) in pea plants?

2) Which cross would produce only white flowers in the offspring if purple flowers (P) are dominant to white flowers (p) in pea plants?

Answer 1

1) The cross between both Heterozygous parents will produce purple and white flowers both.

Parents - Pp(Purple) x Pp(Purple)

Gametes - P ; p P ; p

Offspring - PP ; Pp ; Pp ; pp

Here when P( Purple) is dominant over p(White) then PP and Pp genotype will produce purple phenotype and only pp Genotype will produce white phenotype of flower

Or - a cross between Heterozygote and recessive parent will also produce both purple and white flowers.

Parents - Pp(Purple) x pp (White)

Gametes - P ; p p ; p

Offspring - Pp ; Pp ; pp ; pp

2) Only white flowers can be produced only if both the parents are of recessive genotype or white flowered.

Parents - pp x pp

Gametes - p ; p p ; p

Offsprings - pp ; pp ; pp ; pp

All white flowers in ffsprings can only be produced by this cross otherwise purple flowers will also come.