Question

Both the parents of a child have same type of blood group that is AB. What is the type of blood group that cannot be seen in that child?

• A. O
• B. AB
• C. A
• D. B

Answer 1

The correct option is A O

Alleles I${}^A$ & I${}^B$ are dominant over i and I${}^A$ & I${}^B$ are codominant together.
Parents : I${}^A$I${}^B\times$I${}^A$I${}^B$
Offspring : I${}^A$I${}^A$, I${}^A$I${}^B$, I${}^B$I${}^B$.
So, blood group ‘O’ cannot be seen in the offsprings as both parents lack that allele called i.