Question

First husband of Asha had blood group A and their child blood group O. She remarried. Second husband had blood group B and their child blood group AB. Asha's genotype and blood group is ___________.

• A. $\text{ ii, }O$
• B. $I^{B}i,B$
• C. $I^B{I}^B,AB$
• D. $I^{A}i,A\text{. }$

Answer 1

Answer: (D)

Asha’s child from her first husband had blood group type $O$ i.e., genotype $(ii)$. It means that the child received two recessive alleles, one from each of his parents ($i$ from father and $i$ from mother Asha). Asha’s child from second husband had blood group type $AB$ i.e. genotype $I^A{I}^B$. As the child’s father had blood group type $B$ (genotype $I^{B}i/I^B{I}^B$), it means that the child received $I^B$ allele from father and $I^A$ allele from Asha. Above discussion makes it clear that Asha’s blood group type contains $i$ and $I^A$ genes, thus her blood group type is $A$ with genotype $I^{A}i$