the ratio in a dihybrid test cross between two individuals is given by 2 : 1 1 : 2 : 1 3 : 1 1 : 1 : 1 : 1

In contrast to amonohybrid cross, adihybrid crossis a cross betweenF1offspring (first-generation offspring) of twoindividualsthat differ in twotraitsof particular interest. If the first filial generation (F1generation) produces four identical offspring i.e 1:1:1:1, the second filial generation, which occurs by crossing the members of the first filial generation, shows a phenotypic(appearance) ratio of 9:3:3:1.