Why cant others near different blood groups donate their blood to a tolerant have blood group A?
Answer:
Type A people enjoy a naturally occurring Anti-B antibody contained by their system. If Type B or AB blood (both have the B antigen on the RBC surface) be given to a Type A person, the individual's Anti-B would attach to the B antigen on the donor cell (antigen - antibody reaction). This attachment is not good and would organize to clotting and hemolysis -- a hemolytic transfusion reaction that could front to the death of the Type A creature. Type O blood (which lacks antigens A and B) may be given to Type A people.
Type O can, B and AB will bring transfusion reaction or antibody production.
blood group containing antigen B can't donate because receiver won't be able to see it and will therefore attack the antigen cause blood coagualtion. this is what we observe as transfusion sensitivity and has stony consequences.
Os can - they are universal donors