Agardener 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?