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Question #135893
The Question
Read the following statements regarding ecosystem stability, biodiversity, and the impact of alien species invasions. Which of the following statements is INCORRECT?
Options
- A.
The introduction of the Nile perch into Lake Victoria led to the extinction of over 200 species of cichlid fish, drastically reducing the ecosystem's trophic complexity.
- B.
Invasive species like Eichhornia crassipes can rapidly increase the short-term Net Primary Productivity (NPP) of a water body, temporarily masking the degradation of ecosystem services.
- C.
Based on David Tilman’s long-term experiments, an ecosystem heavily dominated by a single highly productive invasive weed will exhibit decreased year-to-year variation in total biomass.
- D.
The displacement of native species by invasive aliens acts as a catalyst for co-extinctions, effectively removing 'rivets' from the ecosystem airplane as proposed by Paul Ehrlich.
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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
Nile Perch|Lantana camara|Biodiversity Loss
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 conflate 'High Productivity' (rapid biomass generation by weeds) with 'Ecosystem Stability'.
While invasive species create massive short-term NPP, Tilman's experiments prove that true stability (low year-to-year variation) requires high species richness.
A highly productive monoculture of invasives is inherently unstable.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Ecosystem Service Valuation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |