Ans.
Transplantation is defined as a medical method, in which organ or tissues from donor's body are placed in the recipient's body, to replace the missing or damaged organ or tissues.
The immune system of body shows transplant rejection against the transplanted tissue or organ as immune system recognizes it as a foreign antigen. Immune cells act against the transplanted organ and destroy it.
Doctors are able to successfully perform transplant bu using immunosupprresive drugs. These drugs inhibit or prevent the activity of immune system and thus, reduce the chances for transplant rejection.