A plant with purple flowers (PP) is crossed with a plant with white flowers (pp), resulting in offspring with all purple flowers.

Question

The allele for purple color is
.

Answer 1

The allele for purple color is dominant. In this case, the plant with purple flowers has the genotype PP (homozygous dominant), while the plant with white flowers has the genotype pp (homozygous recessive). When these two plants are crossed, all the offspring inherit one dominant allele (P) from the purple-flowered parent and one recessive allele (p) from the white-flowered parent, resulting in a genotype of Pp. Since the purple allele is dominant, all the offspring will display the purple flower phenotype.