Question

Match the following related to combination of parents' blood groups and possible blood types of children.
$\begin{array}{cc}Column-I& Column-II\\ P.AandB& 1.A,B,AB\\ Q.ABandAB& 2.A,B\\ R.OandAB& 3.O\\ S.OandO& 4.A,B,AB,O\end{array}$

• A. P - 4 , Q - 1, R - 3, S - 2
• B. P - 4, Q - 1, R - 2, S - 3
• C. P - 1, Q - 2, R - 3, S - 4
• D. P - 4, Q - 3, R - 2, S - 1

Answer 1

The correct option is B

P - 4, Q - 1, R - 2, S - 3

If parents possess A and B blood groups, they could be homozygous or heterozygous, since heterozygous produces greater number of gamete types, lets consider this scenario. If the parents are heterozygous with A and B blood groups, the gametes produced by one parent would be $\left(I^A\right)$ and i, and gametes produced by the other parent would be $\left(I^B\right)$ and i. Therefore the phenotypes of the offsprings produced by these parents are given in the Punnett square below

If both the parents possess blood group AB, they are heterozygous, and produce the gametes $\left(I^A\right)$ and $\left(I^B\right)$. Therefore the phenotypes produced by these parents are given in the Punnett square below

If the parents possess blood group AB and O respectively, the gametes produced by one parent is $\left(I^A\right)$ and $\left(I^B\right)$ and the other parent is i. Therefore the phenotypes produced by these parents are given in the Punnett square below

If the parents possess blood group O, there is only one type of gamete produced by the parents, that is i. Therefore the phenotypes possessed by their offspring would be (ii), giving rise to only one blood group- blood group O.