Question

Red seed colour shows an $F_2$ ratio of 1 : 4 : 6 : 4 : 1. It is due to

• A. Two polygenes
• B. Different number of dominant genes
• C. Different number of recessive genes
• D. Supplementary genes

Answer 1

Answer: (A)

Two polygenes

Inheritance is controlled by two or more genes in which the dominant alleles have cumulative effect, with each dominant allele expressing a part of functional polypeptide and full trait is shown when all the dominant alleles are present, is called Polygenic or Quantitative inheritance. In the wheat plant kernel colour is controlled by more than two genes. They are red kernel and white kernel. When these both are crossed, in the F2 generation five different phenotypes appear in the ratio of 1:4:6:4:1.

So, the correct option is ‘two polygenes’.