Question: The possible blood groups of children born to parents having A and AB groups are: A). O, A B). A...

Question

The possible blood groups of children born to parents having A and AB groups are:
A). O, A
B). A, B, AB
C). O, A, B
D). O, A, B, AB

Answer 1

Solution

Parents with A and AB blood group cannot have children with O blood group.

Complete answer:
Human blood group inheritance shows an example of codominance as well as multiple alleles.It is governed by three alleles: ${I^A}$ , ${I^B}$ and ${I^O}$ . ${I^O}$ is recessive to both ${I^A}$ ,and ${I^B}$ . ${I^A}$ ,and ${I^B}$ may show codominance.
The parents have A and AB, blood groups. Blood group A indicates that the underlying genotype may be ${I^A}{I^O}$ or ${I^A}{I^A}$ . Blood group AB indicates co-dominance and the underlying genotype must be ${I^A}{I^B}$ . Since we don't know what the genotype of the person with the blood group is, we have to take into account both cases.
In the first case (considering a person with A blood group has $\text{I}^\text{A}$ $\text{I}^\text{O}$ genotype):
${I^A}{I^O}$ (A blood group) × ${I^A}{I^B}$ . (AB blood group).

Gametes	$\text{I}^\text{A}$	$\text{I}^\text{O}$
$\text{I}^\text{A}$	$\text{I}^\text{A}$ $\text{I}^\text{A}$ A blood group	$\text{I}^\text{A}$ $\text{I}^\text{O}$ A blood group
$\text{I}^\text{B}$	$\text{I}^\text{A}$ $\text{I}^\text{B}$ AB blood group	$\text{I}^\text{B}$ $\text{I}^\text{O}$ B blood group

So, the possible $\text{I}^\text{B}$ blood groups of children born in this case are A, B, and AB blood groups.
In the second case (considering a person with A blood group has $\text{I}^\text{A}$ $\text{I}^\text{A}$ genotype):
${I^A}{I^A}$ (A blood group) × ${I^A}{I^B}$ . (AB blood group).

Gametes	$\text{I}^\text{A}$	$\text{I}^\text{A}$
$\text{I}^\text{A}$	$\text{I}^\text{A}$ $\text{I}^\text{A}$ A blood group	$\text{I}^\text{A}$ $\text{I}^\text{A}$ A blood group
$\text{I}^\text{B}$	$\text{I}^\text{A}$ $\text{I}^\text{B}$ AB blood group	$\text{I}^\text{A}$ $\text{I}^\text{B}$ AB blood group

So, the possible blood groups of children born in this case are A and AB blood groups.
In none of the above cases, children have O blood group.
Hence, the correct option is B). A, B, AB

Note: The ABO blood group system was discovered by American biologist Karl Landsteiner in 1901. Hence it is sometimes also called the Landsteiner blood group system.