2023 Manipur Principles of Inheritance and VariationTest cross - expected phenotypic ratio Medium Question 33 of 198 in Principles of Inheritance and Variation

A heterozygous pea plant with violet flowers was crossed with homozygous pea plant with white flower. Violet is dominant over white. Which one of the following represents the expected combinations among 40 progenies formed?

A 30 produced violet and 10 produced white flowers
B 20 produced violet and 20 produced white flowers
C All 40 produced violet flowers
D All 40 produced white flowers

The answer is B.

Solution

Crossing a heterozygous plant (Vv) with a homozygous recessive plant (vv) is a test cross, which is expected to give a 1:1 ratio of the two phenotypes. Among 40 progeny, this is expected to yield 20 violet and 20 white flowered plants.

Concept Test cross - expected phenotypic ratio

Principles of Inheritance and Variation in past papers

198 questions from this chapter have appeared across 27 exam years.