The phenotypic ratio in the F2 generation of a dihybrid cross is

1. A dihybrid cross follows two characters at the same time. 2. In the F2 generation the phenotypes appear in the ratio 9:3:3:1. 3. That ratio can be derived as a combination of the two separate 3:1 ratios. 4. 3:1 alone is the monohybrid F2 ratio, for a single character. _Source: syllabus Biology Ch4 'Principles of Inheritance and Variation'_