Question

Mendel bred a purple-flowered pea plant with a white-flowered pea plant and found that all the offspring had purple flowers. But then when he bred together two of the purple-flowered offspring, some of their offspring had white flowers. Using the concepts of dominant and recessive alleles, explain how the trait of white flowers skipped a generation.

Answer 1

Purple is dominant to white flowered.
Purple gene(which occurs in pairs of PP which are both dominant alleles) crossed with a recessive pp(white flowered) after crossing, all the offspring had Pp. Purple being dominant suppressed the white(p).
after crossing the offspring, (Pp and Pp) a quarter the offspring lacked the dominant allele P hence allowing the recessive colour white to be shown.