A common test to find the genotype of a hybrid is by

1. crossing of one F₂ progeny with female parent
2. studying the sexual behaviour of F₁ progenies
3. crossing of one F₁ progeny with male parent
4. crossing of one F₂ progeny with male parent.

crossing of one F₁ progeny with male parent. e.g

To find the genotype of hybrid test cross is done.