CDS 2026 (I) General Knowledge, question 3

Topic: Biology

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Q3

The antibiotic penicillin can kill invading bacteria without harming human cells because it targets bacterial :

  1. (a) Cell wallCorrect answer
  2. (b) Plasma membrane
  3. (c) Ribosome
  4. (d) Chromosome

Solution.

Answer: (a) Cell wall

  1. Penicillin inhibits bacterial peptidoglycan cell-wall synthesis.
  2. Human cells have no peptidoglycan wall, explaining this selective action.
  3. This does not mean that penicillin can never cause adverse effects, such as allergy.