Question

How does a test cross help to determine the genotype of an individual?

Answer 1

A test cross helps determine the genotype of an individual showing a dominant phenotype by crossing it with a homozygous recessive individual. If all offspring show the dominant trait, the test individual is homozygous dominant. If offspring show a 1:1 ratio of dominant to recessive phenotypes, the individual is heterozygous. This analysis reveals whether the dominant phenotype results from a homozygous or heterozygous genotype.