Question

A child with AB blood group who was born to a mother of the genotype $I^A{I}^A$ cannot have the father of the genotype

• A. $I^A{I}^A$
• B. $I^B{I}^B$
• C. $I^B{I}^B$ and $I^B{I}^O$
• D. $I^B{I}^O$

Answer 1

Answer: (A)

The genotype of the mother is I${}^A$ I${}^A$. A child with blood group AB will have a genotype I${}^A$ I${}^B$. This genotype of the child is possible in 2 cases either if the genotype of the father is I${}^B$ I${}^B$ or I${}^B$ I${}^O$. But a genotype I${}^A$ I${}^A$ of the father will not result in AB blood group of the child. Thus the correct answer is option A.