What are the possible genotypes of a person with type B blood?

A - BB or BO

B - only BB

C - BB or AB

D - only BO

The right answer is BB or BO

The blood group is inherited through a gene located on chromosome 9. Call it the ABO gene. The ABO gene exists in 3 forms, called alleles. We inherit one of these alleles from each of our parents.

The combination of these two alleles is called genotype. The blood group that results from this combination is the phenotype.

* B and B give the BB genotype, which means at the phenotype level, blood group B.

* B and 0 give the B0 genotype, which means at the phenotype level, blood group B, because B is dominant.

Possible genotypes of a type B person would be BB or Bo.