$A$ pair of contrasting characters is termed as

$A$ child has blood group $O$. If the father has blood group $A$ and mother has blood group $B$,work out the genotypes of the parents and the possible genotypes of the other offspring.

$ABO$ blood groups are controlled by the gene:

Identify the wrong statement with reference to the gene $I$ that controls $ABO$ blood groups.

If the father has $AB$ blood group and mother has $A$ blood group,then the children born to them will have the following blood groups $EXCEPT$ . . . . . . .

Multiple alleles are present: