Question

A test-cross distinguishes between

• A. A homozygous dominant and the heterozygous form
• B. A homozygous recessive and the heterozygous form
• C. Two homozygous forms
• D. Two heterozygous forms

Answer 1

Answer: (A)

A homozygous dominant and the heterozygous form

A testcross is a way to explore the genotype of an organism. Testcross is performed to distinguish between pure (homozygous dominant) and hybrid (heterozygous) plant. It involves a cross between an organism with an unknown genotype and an organism that is homozygous recessive for that trait. Test cross helps to determine whether the individual being tested is homozygous dominant (purebred) or heterozygous dominant (hybrid).