In the context of the given picture, answer the following questions:
The molecules shown in the picture are found in the blood. The immune response that they mediate is called:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Humoral immune response
The picture shows an antibody, a Y-shaped molecule of four chains (H2L2) made by B-lymphocytes. Acquired immunity works in two ways: through antibodies, and through T-lymphocytes. The name of the first one comes from where the antibodies are found.
Option (1) Humoral immune response — Correct. Antibodies are found in the blood, so the antibody-mediated response is called the humoral immune response. It is one of the two types of acquired immune response.
Option (2) Cell-mediated immune response — Incorrect. This is the second type of acquired immunity. It is carried out by T-lymphocytes, not by antibodies in the blood. It is responsible for graft rejection.
Option (3) Innate immune response — Incorrect. Innate immunity is the non-specific defence present at birth, given by barriers such as skin, mucus, acid in the stomach and phagocytes. It does not depend on antibodies.
Option (4) Autoimmune response — Incorrect. In an autoimmune response, the immune system attacks the body’s own cells, as in rheumatoid arthritis. It is a disorder, not the name of the antibody response.
Note: A labelled diagram is worth a question or two. Study NCERT figures as carefully as the paragraphs.
NCERT Extract:
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). The T-lymphocytes mediate CMI.”