The genotype of blood group $A$ will be

Sometimes,there are more than two alleles for a given chromosome locus. In this case,a trait is said to be governed by:

In humans,the $ABO$ blood group is controlled by the $I$ gene. It has three alleles: $I^A$,$I^B$,and $i$. Although there are three different alleles,six different genotypes are possible. How many phenotypes are observed in this case?

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

$A$ man with blood group $A$ marries a woman with blood group $AB$. Which type of offspring would indicate that the man is heterozygous for blood group $A$?

In humans,how many genotypes and phenotypes are produced by the three different alleles of the $ABO$ blood group system?