The genotype of blood group $A$ will be

Identify the incorrect statement regarding the gene '$I$' that controls the $ABO$ blood grouping.

$A$ 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 $A$?

How many alleles determine the $A, B, AB,$ and $O$ blood groups in humans?

In Mendel's monohybrid cross,$T$ and $t$ are ......... of each other.

$A$ pair of contrasting characters is termed as