Which one of the following crosses shows the phenotypic ratio of 3:1?

Question

Which one of the following crosses shows the phenotypic ratio of 3:1? (A) AaBb× AaBb (B) aabb× AABb (C) Aabb× Aabb (D) AaBb× aabb

Tardigrade Admin · Accepted Answer

When parents of genotype Aabb is crossed with Aabb we get the following progenies. Ab ab Ab AAbb Aabb ab Aabb aabb Phenotypic ratio will be 3:1 Genotypic ratio will be 1:2:1

Q. Which one of the following crosses shows the phenotypic ratio of 3:1?

$A a B b \times A a B b$

$aabb \times AA B b$

$A abb \times A abb$

$A a B b \times aabb$

When parents of genotype Aabb is crossed with Aabb we get the following progenies.

Ab ab

Ab AAbb Aabb

ab Aabb aabb

Phenotypic ratio will be $3 : 1$
Genotypic ratio will be $1 : 2 : 1$

Q. Which one of the following crosses shows the phenotypic ratio of 3:1?

AaBb×AaBb

aabb×AABb

Aabb×Aabb