Question

A married couple adopted a male child. A few years ,later, twin boys were born to them. The bloodgroup of the couple is AB positive and 0 negative. The blood group of. the three sons is A positive, Bpositive, and 0 positive. The blood group of the adopted son is(a) O positive(b) A positive(c) B positive(d) Cannot be determined on the basis of the given data

Answer 1

c may be because the characters of parents should matched to their children

Answer 2

The blood group of the adopted son will be (a) O positive

One of the parent's blood group is AB⁺, his cell will undergo division to form single chromosome cells during reproduction either A⁺ cell or B⁺ cell.

Other parent has blood group O⁻ which will remain same during reproduction.

Hence the offspring thus produced may have the following configuration :

1) A⁺ and O⁻ results in A⁺

2) B⁺ and O⁻ results in B⁺

hence their offsprings can have only either A⁺ or B⁺ blood groups.

So The blood group of the adopted son will be (a) O positive