The test cross ratio in complementary gene action is

A. 1 : 3

B. 1 : 2 : 3

C. 4 : 1

D. 2 : 1 : 1

Answer: Option A

Solution(By Examveda Team)

The test cross ratio in complementary gene action is 1 : 3.
Complementary gene action is when two different genes work together to contribute to one single trait. These two genes are involved in a specific pathway, like a biochemical reaction, and produce functional products required to produce a certain trait.
The F2 ratio of complementary gene interaction is 9 : 7, whereas the test cross ratio is 1 : 3.