Question

What is a test cross? How does it differ from a reciprocal cross?

Answer 1

Test cross:

1. A test cross is a cross between an organism with an unknown dominant genotype and a homozygous recessive organism for that trait.
2. If any of the offspring from a test cross have the recessive trait, the dominant parent's genotype must be heterozygous.
3. A test cross could be used to determine whether an F₁ plant is homozygous or heterozygous.

Difference between a reciprocal cross and a test cross:

The major difference between the reciprocal cross and test cross is that the reciprocal cross determines sex-linked inheritance, or whether the trait depends on the parent's sex, whereas the test cross determines zygosity, or whether the trait is heterozygous or homozygous.