What is the cross between the progeny of `F_1` and the homozygous recessive parent called ? How is it useful ?

Explanation

When a progeny of `F_1` is crossed with the homozygous recessive parent, it is called Test cross. Thiscrossis helpfulin determining the genotype of an unknownprogeny i.e., whether it is heterozygous or homozygous dominant for the trait.