JEE Main 2023 · 25 January · morning · Single correct · +4 / −1
Which of the following statements is incorrect for antibiotics?
- (a) An antibiotic should promote the growth or survival of microorganisms.
- (b) An antibiotic must be a product of metabolism.
- (c) An antibiotic should be effective in low concentrations.
- (d) An antibiotic is a synthetic substance produced as a structural analogue of naturally occurring antibiotic.
Answer and solution
Answer (a) An antibiotic should promote the growth or survival of microorganisms.
Solution
Chemistry ma’am · 2 steps
Recall the definition: an antibiotic kills or stops microorganisms, so it can never help them grow.
- The definition. An antibiotic is a substance made wholly or partly by microorganisms, or by chemical synthesis. In low concentrations it inhibits the growth of microorganisms or destroys them by interfering with their metabolic processes.
Statement Does it match the definition? (a) Promotes growth or survival of microorganisms No. Antibiotics inhibit or kill microorganisms. (b) A product of metabolism Yes. The original antibiotics, like penicillin, are made by microorganisms during their metabolism. (c) Effective in low concentrations Yes. This is part of the definition. (d) Synthetic structural analogue of a natural antibiotic Yes. The modern definition includes substances made partly or wholly by synthesis. - So. Statement (a) is the incorrect one. It describes the opposite of what an antibiotic does.
The idea to keep. Antibiotic means 'against life': it acts against microorganisms in small doses. It may come from microbial metabolism or be a synthetic copy, but it always inhibits or kills.
Answer from the NTA final answer key. Solution by PrepWiser.