Question

Persons with 'AB' blood group are called as "Universal recipients". This is due to:

• A. Presence of antibodies, anti-A and anti-B, on RBCs
• B. Absence of antibodies, anti-A and anti-B, in plasma
• C. Absence of antigens A and B in plasma
• D. Absence of antigens A and B on the surface of RBCs

Answer 1

The correct option is B Absence of antibodies, anti-A and anti-B, in plasma

ABO blood grouping is based on the presence or absence of two surface antigens A and B on RBC. Antigens are chemicals that can induce immune response.

A person with blood group A has antigen A, blood group B has antigen B, blood group AB has both antigens A and B on the surface of RBCs (red blood cells). But a person of blood group O has no antigen (A and B) on the surface of RBCs.

The plasma of different individuals contains two natural antibodies (proteins produced in response to antigens A and B) namely anti-A and anti-B.

If an antigen is mixed with its corresponding antibodies then it leads to clumping (destruction of RBC).

The person with B blood group has anti-A antibodies and person with A blood group has anti-B antibodies, the one with the O blood group has both anti-A and anti-B antibodies whereas a person with AB blood group has no antibodies against A and B antigens.

As the individuals of AB blood group have no antibodies against A and B antigens, they can receive type AB, O, A, or B red blood cells. Hence individuals of the AB blood group are called universal recipients.