Human body contains blood. In the antigens and antibodies are present antigens are present in the R.B.C.

           Antibodies are present in plasma.

          Antigens are two types. They are" A & B"

          Antibodies are two types. They are " a & b"

             Depending upon the types of antigens and antibodies, the blood can be divided into

         A ---------- Blood group

         B  --------- Blood group

        AB---------- Blood group

        O  ---------- Blood group

   Blood group--A;-  If the blood contais antigen ' A' in RBC and antibody 'b' in the plasma, they are called as blood group " A "

 Blood group--B ;-  If the blood contais antigen " B " in RBC antibody ' b ' in plasma are called as blood group " B "

  Blood group-- AB ;- Blood contais " AB " antigen in RBC and does not contais any antibody in plasma. That is called as blood group " AB "

  Blood group--O:- RBC does not contains any antigen and plasma contais antibody "a & b ". That is called as blood group O.