A dihybrid test cross results in a 50% frequency of recombinants in progeny. This shows that:
1. The two genes are most likely located on different chromosomes
2. One of the genes must be located on the X chromosome
3. The two genes are closely linked on the same chromosome
4. The two genes must be pleiotropic

A dihybrid cross does not give the expected phenotypic ratio in F2 generation. This may be due to
I. Epistasis
II. Multiple genes affecting your trait of interest
III. Linkage
1. I & II only
2. I &III only
3. II & III only
4. I, II & III