UPSC Prelims 2024 · GS Paper I
Question 29: Environment and Ecology
Consider the following :
- 1.Butterflies
- 2.Fish
- 3.Frogs
How many of the above have poisonous species among them ?
AnswerUPSC’s answer is (c).
Poisonous species occur in all three groups. Some butterflies, such as the monarch, are toxic because their caterpillars store poisons from their food plants. Many fish, such as pufferfish, carry toxins in their organs. Frogs include the poison dart frogs of tropical America, whose skin secretions are toxic. So all three groups have poisonous species.
- 1. Some butterflies, like the monarch, are poisonous to predators.
- 2. Some fish, like pufferfish, are poisonous.
- 3. Some frogs, like poison dart frogs, are poisonous.
How you could have got this
No shortcut here: in a “how many” question, ruling out options doesn’t help. Every statement has to be judged.
Which options go is worked out from UPSC’s key and the options, not by a model.
Why each option is right or wrong
- (a) Wrong: poisonous species exist among butterflies, fish and frogs.
- (b) Wrong: all three groups contain poisonous species.
- (c) Right: butterflies, fish and frogs all include poisonous species.
- (d) Wrong: poisonous species exist in each group.
Answer: UPSC’s key. Explanation: written by UPSC Grade, not by UPSC.
Source: UPSC, Civil Services (Preliminary) Examination 2024, General Studies Paper I, Series A. The paper on upsc.gov.in.