Read the following statements:
Statement I: B-cells are responsible for antibody-mediated immune response.
Statement II: The primary function of B-cells is to secrete antibodies into the body fluids.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Both statement I and statement II are correct.
Acquired immunity works through two kinds of lymphocytes, B-lymphocytes and T-lymphocytes. B-lymphocytes release proteins called antibodies into the blood. Because the antibodies are found in the blood (a body fluid), this response is called the humoral or antibody-mediated immune response. T-lymphocytes do not secrete antibodies; they mediate cell-mediated immunity.
Statement I: B-cells are responsible for antibody-mediated immune response. — True. The antibodies made by B-cells carry out the humoral immune response, which the book names as the antibody mediated type of acquired immunity.
Statement II: The primary function of B-cells is to secrete antibodies into the body fluids. — True. B-lymphocytes produce an army of antibodies into the blood in response to pathogens. T-cells do not secrete antibodies themselves; they help B-cells to produce them.
NCERT Extract:
Acquired Immunity – “… The B-lymphocytes produce an army of proteins in response to pathogens into our blood to fight with them. These proteins are called antibodies. The T-cells themselves do not secrete antibodies but help B cells to produce them.”
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).”