Question

The phenotypic ratio of a monohybrid cross is _________

• A. 3:1
• B. 1:2:1
• C. 4:1
• D. 1:1

Answer 1

The correct option is A

3:1

Phenotypic ratio is the ratio of visible tratis, i.e. out of the total number of offspring how many express the dominant trait and how many express the recessive trait. In the F2 generation of a typical monohybrid cross, we get four combinations. But the phenotypes of the organisms appear as: 3 organisms express the dominant trait while only one expresses the recessive trait. Thus, the phenotypic ratio becomes 3(dominant):1(recessive)