Question

In a cross between AABB $\times$ aabb, the ratio of $F_2$ genotypes between AABB, AaBB, Aabb and aabb would be

• A. 9 : 3 : 3 : 1
• B. 2 : 1 : 1 : 2
• C. 1 : 2 : 2 : 1
• D. 7 : 5 : 3 : 1.

Answer 1

Answer: (C)

1 : 2 : 2 : 1

When a cross is made between AABB x aabb. In the F2 generation the genotypic ratio is AABB – 1 AABb – 2 AaBB – 2, AaBb – 4 AAbb – 1, Aabb – 2, aaBB – 1,aaBb – 2 aabb – 1.

So, the correct option is ‘1:2:2:1’.