Question
GeneralGeneralGeneral

What is a test cross? Give examples.

Verified Answer

A test cross is the crossing of an individual showing a dominant trait with a homozygous recessive individual to determine the unknown genotype of the dominant individual.

Example:

  • T_ × tt

  • If all offspring are tall, the parent is TT.

  • If offspring are tall and dwarf in a 1:1 ratio, the parent is Tt.

Quick Fact: Test crosses were widely used by Mendel to identify hidden recessive alleles.