Consider the following : 1. Butterflies 2. Fish 3. Frogs How many of the above have poisonous species among them ?
- (a) Only one
- (b) Only two
- (c) All three ✓ UPSC's answer
- (d) None
Why the answer is (c)
• Poisonous species — those harmful when touched or eaten — occur in all three groups.
• Butterflies such as the monarch and India's common crow and plain tiger sequester toxic alkaloids or cardiac glycosides from their larval food plants, making them unpalatable and poisonous to predators (item 1).
• Fish such as the pufferfish carry tetrodotoxin, one of the deadliest natural poisons, and some Indian coastal fish are toxic when eaten (item 2).
• Frogs such as the poison-dart frogs of Central and South America secrete potent skin toxins; many toads and frogs have irritant or toxic skin secretions (item 3).
• Hence all three, option (c).
Why the other options are wrong
- (a) Only one
- All three groups, not one, include poisonous species.
- (b) Only two
- Butterflies, fish and frogs all have poisonous members.
- (d) None
- Each group contains poisonous species.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.