Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Tissue matching and blood group matching are essential before undertaking any graft or transplant.
Reason (R): The humoral immune response is responsible for graft rejection.
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) is correct but (R) is not correct.
Acquired immunity is of two types. In the humoral (antibody-mediated) response, B-lymphocytes make antibodies that are found in the blood. In the cell-mediated response, T-lymphocytes act directly. The body can tell ‘self’ from ‘nonself’, and a graft from another person is seen as nonself.
Assertion (A): Tissue matching and blood group matching are essential before undertaking any graft or transplant. — True. A graft from just any source would be rejected sooner or later. So tissue matching and blood group matching are done before any graft or transplant, and even after this the patient has to take immuno-suppressants all his or her life.
Reason (R): The humoral immune response is responsible for graft rejection. — False. Graft rejection is due to the cell-mediated immune response, carried out by T-lymphocytes. The humoral response works through antibodies in the blood and is not the response the book names for graft rejection. Changing “cell-mediated” to “humoral” makes R false.
NCERT Extract:
Acquired Immunity – “… Grafts from just any source – an animal, another primate, or any human beings cannot be made since the grafts would be rejected sooner or later. Tissue matching, blood group matching are essential before undertaking any graft/transplant and even after this the patient has to take immuno–suppresants all his/her life. The body is able to differentiate ‘self’ and ‘nonself’ and the cell-mediated immune response is responsible for the graft rejection.”
Acquired Immunity – “… Because these antibodies are found in the blood, the response is also called as humoral immune response. This is one of the two types of our acquired immune response – antibody mediated. The second type is called cell-mediated immune response or cell-mediated immunity (CMI).”