Which one of the following statements is correct about effects of antibiotics on viruses?
- (a)Viruses are "non-living" entities but it can interact with antibiotics
- (b)Taking antibiotics cures viral infections
- (c)Viruses do not possess metabolic pathways on which antibiotics can function, whereas bacteria have such pathways
- (d)Viruses are resistant to antibiotics
Correct — C, viruses do not possess metabolic pathways on which antibiotics can function, whereas bacteria do. Antibiotics work by attacking processes unique to living bacterial cells - building the cell wall, making proteins on bacterial ribosomes, and copying DNA. Viruses are not cells and carry out none of these processes on their own; they hijack the host cell's machinery, so there is nothing for an antibiotic to act on. That is why antibiotics cure bacterial infections but not viral ones.
- (a)Viruses are "non-living" entities but it can interact with antibiotics — Viruses lack the metabolic machinery that antibiotics target, so antibiotics do not meaningfully act on them; the statement wrongly implies a useful interaction.
- (b)Taking antibiotics cures viral infections — This is false and unsafe - antibiotics do not cure viral infections such as colds or flu, and misusing them this way only drives antibiotic resistance.
- (d)Viruses are resistant to antibiotics — This is misleading; 'resistance' means an organism evades a drug that would otherwise act on it, but antibiotics have no target in a virus at all, so it is not a case of resistance.
Antibiotics act on processes specific to living bacterial cells - cell-wall synthesis, bacterial ribosomes and DNA or RNA replication. Viruses are acellular and have no independent metabolism; they multiply only inside a host cell using its machinery, so antibiotics have nothing to attack in a virus.
Only one option gives the correct mechanism. Option (b) is the popular misconception, and option (d) confuses 'no target at all' with true drug 'resistance'.
- Antibiotics target bacteria-specific processes - cell-wall synthesis, bacterial ribosomes and DNA/RNA replication - that viruses lack.
- Viruses are acellular and have no independent metabolism; they replicate using the host cell's machinery.
- Viral infections are treated with antiviral drugs or prevented by vaccines, not by antibiotics.
- Overusing antibiotics for viral illnesses promotes antibiotic resistance in bacteria.
Antibiotics act on bacterial life processes; viruses have none, so antibiotics do not work on them.
- Believing antibiotics cure colds or flu - those are viral illnesses.
- Calling a virus's non-response to antibiotics 'resistance' when there is simply no target.
- Assuming a virus is an ordinary living cell with its own metabolism.
NDA and UPSC ask why antibiotics do not work on viruses - key on viruses lacking the metabolic pathways antibiotics target.
Which of the following statements is/are correct? 1. Viruses lack enzymes necessary for the generation of energy. 2. Viruses can be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only.
- (a) 1 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Answer(a) 1 only - viruses lack energy-generating enzymes; they cannot be grown on synthetic media and are not spread only by biological vectors.
Directly underpins this answer - because viruses have no energy-generating enzymes or metabolic pathways, antibiotics (which target such processes) have nothing to act on.
Which one of the following statements regarding viruses is not true?
- (a) Viruses need living cells to reproduce.
- (b) All viruses are parasites.
- (c) Viruses can synthesize their food through photosynthesis.
- (d) Viruses are similar to chemical substances outside the host.
Answer(c) Viruses can synthesize their food through photosynthesis.
Same virus-biology theme - viruses lack independent metabolism (no photosynthesis, no energy generation), the very reason antibiotics fail against them.
Initial discovery of antibiotic penicillin was done by
- (a) Francis Crick
- (b) Maurice Wilkins
- (c) Charles Darwin
- (d) Alexander Fleming
Answer(d) Alexander Fleming
Companion antibiotic item - penicillin and other antibiotics act on bacterial processes, which viruses lack, so they cannot treat viral infections.
- practice — not a real PYQ
Antibiotics are ineffective against viral diseases because viruses
- (a)are too small
- (b)lack the metabolic machinery that antibiotics target
- (c)live outside the body
- (d)have a thick cell wall
Answer(b) lack the metabolic machinery that antibiotics target - so there is nothing for the drug to act on.
- practice — not a real PYQ
Which of the following is used to treat or prevent a viral infection?
- (a)an antibiotic
- (b)an antiseptic
- (c)a vaccine or antiviral drug
- (d)an analgesic
Answer(c) a vaccine or antiviral drug - antibiotics do not work against viruses.