TEST CROSS: In test cross, F1 hybrid is crossed back with the recessive parent. In other words, test cross is the cross between a dominant phenotype (TT or Tt) and a homozygous recessive (tt).
BACK CROSS: In back cross, F1 hybrid is crossed back with any of the parent, either dominant or recessive. Back crosses are used to increase useful traits in a population. For example, certain crop plant hybrids are backcrossed with wild species (parent) to obtain its useful traits such as disease resistance.
In both crosses, F1 generation is crossed with the parents so in this way they are similar but actually they are different because during backcross, F1 hybrid is crossed back with any of the parents, eit her homozygous or heterozygous. However, during test cross, F 1 hybrid is always crossed back with the recessive parent. Hence,all test crosses are considered as backcrosses, but all backcrosses are not the test crosses.
Hope it helps
cHeErS!! :)
