Question

Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white-flowered pea plants. These results are consistent with which set of parents?

Answer 1

Answer:

Heterozygous purple-flowered parents

Explanation:

A cross involving two heterozygous parents for a dominant trait always segregates in 3:1 phenotypic ratio according to Mendel's law of segregation.

In this case, if purple flower colour is dominant over white flower colour and the trait is represent by P, the heterozygous purple-flowered pea plants will be Pp. If two heterozygous individuals are crossed,

Pp   x   Pp    = PP, Pp, Pp, pp

Since P is a dominant allele, the phenotypic ratio will be 3 purple to 1 white.

Hence, the results are consistent with heterozygous purple-flowered parents.