Short Answer Question
Write a note on antigens on blood cells.
There are several known antigens on the surface of human red blood cells. These antigens give rise to different blood groups.
ABO Blood Groups:
The A, B, and O blood groups were discovered by Karl Landsteiner in 1900.
He found two antigens or agglutinogens on the surface of human red blood cells and named them as antigen A and antigen B. He also noticed the corresponding antibodies or agglutinins in the serum called ‘a’ and ‘b’.
|Blood group||Genotype||An antigen on the Surface of RBC||Antibody in Serum||Can donate blood to||Can receive blood from|
IA IA or
|A||Antibody b||A, AB||A, O|
IB IB or
|B||Antibody a||B, AB||B, O|
|AB (universal acceptor)||IA IB||A and B||Nil||AB||A, B, AB, O|
|O (universal donor)||IO IO||Nil||Both Antibody a and Antibody b||A, B, AB, O||O|
In ABO system, the blood groups are determined by the presence or absence of antigen A and antigen B. The blood group of a person is classified into four groups A, B, AB, and O.
Blood group A: Individuals, with blood group ‘A’, has the antigen A on the surface of their red blood cells (RBCs) and antibody ‘b’ in their plasma.
Blood group B: Individuals with blood group ‘B’ have the antigen B on the surface of their RBCs and antibody ‘a’ in their plasma.
Blood group AB: Individuals with blood group ‘AB’ have both antigens A and B on the surface of their RBCs and no antibodies in their plasma.
Blood group O: Individuals with blood group ‘O’ lack both antigens A and B on the surface of their RBCs and show the presence of both ‘a’ and ‘b’ antibodies in their plasma.
Rh factor: Rh – factor is an antigenic protein present on the surface of the red blood cells in human beings.