Question

How many possible blood antigen combinations are there?

Answer 1

there are two types of antigens in ABO human blood grouping system.

Explanation:

there are two antigens in ABO human blood grouping system:

A

B

These antigens form four types of blood groups:

- A only A antigen present

- B only B antigen present

- AB both A and B antigens present

- O neither A nor B antigen present

Each blood group may be either Rh positive or Rh negative, due to presence or absence of rhesus antigen.