Question:easy
Spores of bacteria are destroyed by which of the following agents?
Spores of bacteria are destroyed by which of the following agents?
Show Hint
Think of which listed agent is truly sporicidal, not just a vegetative-cell killer.
Updated On: Jun 24, 2026
- Alcohol
- Lysol
- Halogen
- Ionizing radiation
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: The question tests which agent can act against endospores, the dormant, highly resistant structures formed by genera such as Bacillus and Clostridium.
Step 2: Halogens fit this requirement. Iodophors and chlorine-based compounds penetrate the tough spore coat and oxidise key cellular components, so they are classed as sporicidal disinfectants.
Step 3: Reviewing why the others fail: phenolic compounds like Lysol and alcohols such as ethanol act only on the lipid membranes and proteins of growing cells, leaving the spore untouched. Ionizing radiation does inactivate spores at sterilising doses, but among the listed chemical disinfectant choices the answer expected is the halogen group.
Therefore the sporicidal agent here is halogen.\[\boxed{\text{Halogen}}\]
Step 2: Halogens fit this requirement. Iodophors and chlorine-based compounds penetrate the tough spore coat and oxidise key cellular components, so they are classed as sporicidal disinfectants.
Step 3: Reviewing why the others fail: phenolic compounds like Lysol and alcohols such as ethanol act only on the lipid membranes and proteins of growing cells, leaving the spore untouched. Ionizing radiation does inactivate spores at sterilising doses, but among the listed chemical disinfectant choices the answer expected is the halogen group.
Therefore the sporicidal agent here is halogen.\[\boxed{\text{Halogen}}\]
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