Question

gardener purchased 20 full-grown pea plants. All 20 were the same genotype and had purple flowers. The gardener crossed two of these plants to get seeds for the next season. The seeds from the cross produced some plants with purple flowers and some with white flowers. The gardener learned that in pea plants the allele for purple flowers (P) is dominant of the allele for white flowers (p). What was the most likely genotype of the original 20 full-grown plants?

Answer 1

maybe 75% of them were purple and 25% were white

Answer 2

"Pp" is the most likely genotype of the original 20 full-grown plants

Step-by-step explanation:

Given

All the 20 full-grown pea plants have purple flowers.

But when two plants out of these 20 are mated , then the seeds from the cross produced some plants with purple flowers and some with white flowers

This leads to a conclusion that though the 20 plants have purple color , they must be carrier of white color allele.

Thus, genotype of all the 20 pea plant species would be "Pp"

if two "Pp" genotype plants are crossed following offsprings are produced -

P p

P PP Pp

p Pp pp

Since "p" is a recessive allele , therefore when two recessive alleles are together they express their trait.

So, here in this case one out of four offspring is white in color.