A reciprocal cross means that the same two parent are used in two experiments in such a way that if in one experiment A is used as the female parent and B is used as the male parent then in the other experiment A will be used as the male parent and B as the female parent. Thus the sources of gametes are reversed. When the F, individuals obtained in a cross is crossed with the recessive parent, it is called a test cross. When inheritance of two pairs of contrasting character is studied simultaeneously it is called dihybrid cross.