Which one of the following statements best describes the role of B cells and T cells in the human body ?
- (a) They protect the body from environmental allergens.
- (b) They alleviate the body's pain and inflammation.
- (c) They act as immunosuppressants in the body.
- (d) They protect the body from the diseases caused by pathogens. ✓ UPSC's answer
Why the answer is (d)
• B cells and T cells are lymphocytes, the core of the adaptive immune system.
• B cells produce antibodies that bind and neutralise pathogens; T cells include helper cells that coordinate the response and killer cells that destroy infected cells; both form memory cells for lasting immunity.
• Their role is therefore protection against diseases caused by pathogens — bacteria, viruses, fungi, parasites — option (d).
• They do not primarily target environmental allergens (allergy is an over-reaction), do not relieve pain, and are not immunosuppressants.
• Vaccines work by training B and T cells.
• Hence option (d).
Why the other options are wrong
- (a) They protect the body from environmental allergens.
- Allergen reactions are an over-response, not the cells' protective role.
- (b) They alleviate the body's pain and inflammation.
- Lymphocytes do not relieve pain or inflammation.
- (c) They act as immunosuppressants in the body.
- They activate immunity; they are not immunosuppressants.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2022, held on 5 June 2022. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.