Question

What are the different blood group in human beings? what is the basis of grouping them? ​

Answer 1

Answer:

Blood Groups:

There are more than 30 antigens on the surface of blood cells that give rise to different blood groups. In a blood transfusion, certain blood groups, e.g., ABO blood group, of the recipient and donor must be matched, otherwise the recipient’s immune system will produce antibodies that cause agglutination of the transfused cells and block blood circulation through capillaries.

Two types of blood groups — ABO Blood Group and Rh Blood Group (Rh Factor) are widely used all over the world.

ABO Blood Groups:

Karl Landsteiner reported first time ABO blood groups in human beings. A, В and О blood groups were discovered by Landsteiner (1900) while AB group was found out by de Castello and Steini (1902). ABO blood groups are determined by the gene I (isoagglutinin).

There are three alleles, IA, IB and I° of this gene. Proteins produced by the IA and IB alleles are called A antigen and В antigen. People with blood group A have the A antigen on the surface of their RBCs, and antibodies to antigen В in their plasma.

Persons with blood group В have В antigen on their RBCs, and antibodies against A antigen in their plasma. Individuals with AB blood group have both antigen A and antigen В on their RBCs, and no antibodies for either of the antigens in their plasma.

Type О individuals are without A and В antigens on their RBCs, but have antibodies for both these antigens in heir plasma. Individuals with blood group AB can receive blood of A, В or О group, while those with blood group О can donate blood to anyone.

This is the most important blood group for transfusion. Thus person with blood group AB is called universal recipient and person with blood group О is called universal donor. If a blood transfusion is made between an incom­patible donor and recipient, reaction of antigens on the cells and antibodies in the plasma produces clots that clog capillaries.

Human ABO Blood groups and their compatibility  

Rh (Rhesus) Blood Group:

A protein named as rhesus antigen, is present on the surface of red blood corpuscles in many persons. It was discovered in 1940 by Landsteiner and Wiener in the blood of Rhesus monkey, hence its name. Depending on the race, 85 to 99 percent of the white population have this rhesus antigen (also called Rh factor) and are called Rh positive (Rh+).

Others who do not have this factor arc known as Rh negative (Rhr). Rh+ is dominant to Rh–. Whites Rh+ 85%, Rh– 15%, American Blacks Rh+ 95%, Rh– 5%, African Blacks Rh+ 100%.

Formation of Rh protein is controlled by a dominant gene which may be called as R. Thus, RR (homozygous) and Rr (heterozygous) persons are dominant and are Rh positive and rr (homozygous) are recessive and are Rh– negative. Both Rh+ and Rh– individuals are phenotypically normal. The problem arises during blood transfusion and pregnancy.

Explanation:

ABO blood group system, the classification of human blood based on the inherited properties of red blood cells (erythrocytes) as determined by the presence or absence of the antigens A and B, which are carried on the surface of the red cells. Persons may thus have type A, type B, type O, or type AB blood.