Question

Define test cross.

Answer 1

The phenomenon of test cross was first introduced by Gregor Mendel. When F${}_1$ hybrid is crossed back only with homozygous recessive parent, this is called as the test cross. This is used to determine the genotype of an individual with dominant character. If all the offspring has Pp, then the parent is PP. If half the offsprings are Pp and half offspring are pp, then the parent is Pp.