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Question #135666
The Question
Assertion (A): According to Paul Ehrlich's Rivet Popper hypothesis, the extinction of a keystone species poses a more immediate threat to ecosystem stability and its service valuation than the loss of a functionally redundant species. Reason (R): Keystone species disproportionately regulate trophic cascades and functional biodiversity, meaning their removal triggers a systemic collapse that degrades ecosystem services.
Options
- A.
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
- B.
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
- C.
Assertion is correct but Reason is incorrect.
- D.
Assertion is incorrect but Reason is correct.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Ecosystem Service Valuation|IUCN Red List Data|Rivet Popper Hypothesis
Why This Question Is Tricky
Examiner Levers
Logical Assertion
Tests the causal relationship between two true statements.
Difficulty Boost : +4Common Mistakes
Conceptual Pivot: Students often memorize the Rivet Popper hypothesis (airplane = ecosystem, rivet = species) without connecting the 'wing rivet' metaphor specifically to the concept of 'Keystone Species' and 'Trophic Cascades' which maintain ecosystem services.
The trap is failing to synthesize Ehrlich's hypothesis with Costanza's ecosystem service valuation and the disproportionate ecological role of keystone species.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biodiversity and Conservation - Class 12 |
| Concept | IUCN Red List Data |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |