Quantrex Academy · Free NEET PYQ solutions
NEET Zoology Principles of Inheritance and Variation 2026 NEET 2026 (Cancelled)

NEET Zoology Question (2026) — Solution

Question

What is the probability of having children with 'O' blood group, where both mother and father are heterozygous for 'A' and 'B' blood group, respectively ?

Options

  1. A. 25\%
  2. B. 0\%
  3. C. 75\%
  4. D. 50\%

Answer

A. 25\%

Step-by-step solution

The genotype of the mother, who is heterozygous for 'A' blood group, is I^ A i. The genotype of the father, who is heterozygous for 'B' blood group, is I^ B i. A cross between the mother and father (I^ A i I^ B i) produces the following possible genotypes in the offspring: I^ A I^ B (AB blood group) I^ A i (A blood group) I^ B i (B blood group) ii (O blood group) Out of the four possible combinations, only one results in the 'O' blood group (ii). The probability of having a child with 'O' blood group is 1 4 . In percentage, this is 1 4 100\% = 25\%. Answer: 25\%

Practice more on Quantrex App →

Related: Zoology — Principles of Inheritance and Variation · All PYQ Banks