If two genes on the same chromosome exhibit complete linkage, what is the expected F2 phenotypic ratio from a selfed heterozygote with the genotype a + b + ⁄⁄ ab?

3:1

Explanation:

It should be understood that ,each parent produces two types of gametes, a+b+ and ab, giving the simple Mendelian ratio of 3 a+b+ : 1 ab.

Note that, the Mendelian ratio explains the phenotypic ratio of different types of individuals that is occurring at the F2 generation of a monohybrid cross, that is, a cross between two individuals that have homozygous genotype.

This is one of the Mendel's insight in the field of genetics.