Q. Write short notes on Blood Groups. (40 BPSC/1995)

Q. Write short notes on Blood Groups. (40 BPSC/1995)
The blood groups are a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These are inherited and represent contributions from both parents. A total of 36 human blood group systems and 346 antigens are now recognized by the International Society of Blood Transfusion.
The main reason behind the difference in blood of human is the glyco protein which is found in Red Blood Corpuscles called antigen.

• Antigen are of two types- Antigen A and Antigen B.
• On the basis of presence of Antigen or Glyco Protein, there are four group of blood in human:
  • (a) That contains Antigen A- Blood Group A.
  • (b) That contains Antigen B- Blood Group B.
  • (c) That contains both the Antigens A and B – Blood Group AB.
  • (d) That contains neither of the Antigens-Blood Group O.

An opposite type of protejn, is found in blood plasma. This is called antibody.

• This is also of two types – Antibody ‘a’ and Antibody b’.

Therefore, with the four groups of blood division of antibody is as under-

• Blood Group: A -> Antigen (In Red Blood Corpuscles): Only ‘A’   -> Antibody (In plasma) : Only ‘b’
• Blood Group: B -> Antigen (In Red Blood Corpuscles):  Only ‘B’-> Antibody (In plasma) : Only ‘a’
• Blood Group: AB -> Antigen (In Red Blood Corpuscles): Both ‘A’ and ‘B’ -> Antibody (In plasma) : Absent
• Blood Group: O -> Antigen (In Red Blood Corpuscles):  Absent -> Antibody (In plasma) : Both ‘a’ and ‘b’

Blood Transfusion: 

• Antigen ‘A’ and antibody ‘a’, Antigen B’ and antibody ‘b’ cannot live together. In case of so happened these get most sticky, which spoils the blood. This is called agglutination of blood.
• Therefore, in blood transfusion adjustment of Antigen and Antibody should be done carefully so that agglutination of blood do not takes place.
• Blood Group O is called Universal Donor because it does not contain any antigen.
• Blood Group AB is called Universal Receptor because it does not contain any antibody.
• Rh factor: It a different type of antigen in the blood.  In the blood of that person it is found, their blood is called Rh-positive and in the blood of that person it is not found, is called Rh-negative.
  • At the time of blood transfusion Rh-factor is also tested. Rh+ is given to Rh+ and Rh-is given Rh-blood only.
  • If the blood of Rh+ blood group is transferred to a person with Rh-blood group, then due to the less quantity for the first time there does not seem any bad effect but if this process is repeated then due to agglutination the person with Rh-blood group dies.
    • e.g. Erythroblastosis Foetalis : If the father’s blood is Rh+ and the mother’s blood is Rh- then the child to be born dies at the pregnancy or short span of time after the birth.

Based on the blood group of parents the child blood group can be expected.  e.g. 

• If the Blood group of Mother and father is OxO then the expected blood group of child is O. 
• If the Blood group of Mother and father is OxA then the expected blood group of child is O, A.
• the Blood group of Mother and father is AxA then the expected blood group of child is O,A. 
• the Blood group of Mother and father is ABxAB then the expected blood group of child is A,B,AB.