How does a test-cross help in identifying the genotype of the organism ? Explain.

Explanation

A Test- cross is a cross between an individual of unknown gentype and an individual which is homozygous recessive for trait.
1 If the individual is homozygous dominant, all the individuals int heprogeny would be dominant

2. If the individual is heterozygous, the progeny will show dominant phenotype and recessive ones in the ratio of 1 : 1.

Phenotypic ratio : 1 : 1.