In a marriage between a male with blood group A and a female with blood group B, the progeny had either blood group AB or B. What could be the possible genotype of the parents?

1. I^A i (Male) ; I^B I^B (Female)

2. I^A I^A (Male) ; I^B I^B (Female)

3. I^A I^A (Male) ; I^B i (Female)

4. I^A i (Male) ; I^B i(Female)

ABO blood groups in humans are controlled by the gene I. It has three alleles – I^A I^B and i. Since there are three different alleles, six different genotypes are possible. How many phenotypes can occur?

1. Three

2. One

3. Four

4. Two

ABO blood grouping is controlled by gene I which has three alleles and shows co-dominance. There are six genotypes. How many phenotypes in all are possible?

ABO blood group has:
1.  Two codominant and one recessive allele
2.  Two codominant and two recessive allele
3.  Two incompletely dominant genes
4.  Two pseudo alleles