Question

In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow and green seeded plants would you expect in F1 generation ?

Answer 1

Answer:

The ratio of yellow and green seeded plants in F1 generation is 1:1.

Explanation:

This can be solved as follows:

Let the gene for yellow and green seeded plant be Y and y respectively.

Parent generation:

Gametes: Yy ( yellow seeded plant), yy( green seeded plant)

The two plants are crossed:

Yy     X     yy

F1 generation:  Yy, Yy, yy, yy

Since Y is dominant, therefore, Yy is yellow seeded whereas yy is green seeded plant. ( y can only be expressed if Y is absent)

Genotypic ratio: 1:1  ( two Yy and two yy so 2:2 which is equivalent to 1:1)

Phenotypic ratio: 1:1 ( two yellow and two green so 1:1)