Question

a polgenic trait is controlled by three genes A,B,C.in a cross AaBbCc. and AaBbCc ,the phenotypic ratio of the offspring was observed as 1:6:X:20:X:6:1 ,what is the possible value of X​

Answer 1

Answer:

• In polygenic inheritance, a particular trait is controlled by 3 different genes. The given problem is of polygenic inheritance. In this, phenotypic ratio is 1:6:15:20:15:6:1 :)

instead of 27:9:9:9:3:3:3:1 in F 2 generation.

• In the given example, the genotype of parents is AaBbCc and AaBbCc. They will produce gametes

ABC, ABc, Abc, abc, aBC, aBc, abC, AbC.

The phenotypic ratio will be 1:6:15:20:`15:6:1.

The phenotypic ratio will be

1:6:15:20:`15:6:1.Thus, the correct answer is '15.'