- a.Viruses take refuge in a cell organelle where antibiotics cannot reach.
- b.Viruses neither have cell walls nor their own metabolic machinery that can be targeted by antibiotics.
- c.Viruses mutate rapidly.
- d.None of the above
Answer: (B) Viruses neither have cell walls nor their own metabolic machinery that can be targeted by antibiotics.
Antibiotics act on structures and processes found only in bacteria: the peptidoglycan cell wall (penicillin), the 70S ribosome (streptomycin, tetracycline) or bacterial enzymes for copying DNA (ciprofloxacin). A virus is just nucleic acid inside a protein coat; it has no cell wall, ribosomes or metabolism of its own and multiplies by using the host cell's machinery, so an antibiotic has nothing to attack. Option C is a true statement about viruses but explains why vaccines and antiviral drugs lose effect, not why antibiotics fail; option A is false. Viral infections are handled with antivirals (acyclovir, oseltamivir) and prevented by vaccines. Needless antibiotic use promotes antimicrobial resistance (AMR). Penicillin was discovered by Alexander Fleming in 1928.