Question

In pea plants, plant height is controlled by a single autosomal dominant gene. Tall plants (H) are dominant to short plants (h). A tall plant with the genotype capital H lowercase h crossed to a tall plant with the genotype capital H lowercase h.

In a cross of two tall heterozygous plants, which phenotype ratio is expected from the resulting offspring?
a. 3:1
b. 9:3:31
c. 1:1
d. 1:2:1

Answer 1

Answer:a). 3:1

Explanation: A cross between two heterozygous tall plants with genotype Hh will produce one HH, two Hh and one hh. HH will manifest as tall plants, Hh will manifest as tall plants while hh will manifest as short plants.

Therefore, the phenotype ratio is three tall plants to one short plant, that is, 3:1.

See the attached punnet square for more information