1997 General Studies, all questions
UPSC Prelims 1997 · General Studies
Question 129: Science and Technology
Antigen is a substance which
alowers body temperature
bdestroys harmful bacteria
ctriggers the immune system
dis used as an antidote to poison
AnswerThe answer is (c).
An antigen is any substance, often a protein on a germ or a foreign cell, that the body recognises as foreign and that triggers the immune system to make antibodies. Vaccines contain harmless antigens to prepare the body in advance. An antidote counters a poison, and it is antibodies, not antigens, that attack bacteria.
Why each option is right or wrong
- (a) Antigens do not lower body temperature.
- (b) Destroying bacteria is the work of antibodies and white cells.
- (c) Right: an antigen triggers the immune system.
- (d) An antidote is a different thing: it counters a poison.
Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 1997, General Studies. UPSC's own paper isn't online; the words are from a published compilation. The paper on upsc.gov.in.