[A]: Organ transplantation patients are given immunosuppressive drugs.
[R]: Transplanted tissue has antigens which stimulate the specific immune response of the recipient

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark a
B. lf both Assertion & Reason are true but the reason is no t the correct explanation of the assertion, then mark b
C. If Assertion is true statement but Reason is false, then mark c
D. If both Assertion and Reason are false statements, then mark d.

Answer

A

Explanation

An organ transplant is the transplantation of an organ (or part of one) from one body to another, for the purpose of replacing the recipient's damaged or failing organ with working one from the donor. Organ donors can be living, or cadaveric (dead). Immunosupperssive drug are any of a variety of substances used to prevent production of antibodies. The are clinically used to prevent rejection by a recipient's body of an organ (e.g. bone marrow, heart, kidney, liver) transplanted from a donor. A transplant is rejected when the recipient's immune system acts against it. treatment of autoimmune diseases or diseases that are most likely of autoimmune orgin (e.g. rheumatoid arthritis). The steroids, such as cortisone, which suppress the antibody-forming lymphocyte cells, have been used to prolong human organ transplant. Steroids may also prevent antigens from entering cells and thereby prevent local allergic inflammation reactions. In another immuno-suppressive method, human lymphocytes are injected into horses, stimulating the animals to produce antilymphocyte serum. The serum, administered to humans with transplanted organs, in some way inactivates lymphocyte cells. Another group of immunosuppressive drugs act by interfering with the synthesis of nucleic acids and are especially effective against proliferating cells such as stimulated lymphocytes. Some of these are analogs of purines and pyrimidines, substances that are nucleic acid subnits, the purine analog azothioprine has been used to suppress rejection of transplanted human kidneys. Most substances that inhibit nucleic acid synthesis, such as nitrogen mustard, cyclophosphamide (Cytoxan), chloramphenicol, actionomycin, and colchicine, are not widely used clinically because they are too toxic.