Before You Begin
Question #46691
The Question
An aggressive alien fish species is introduced into a stable lake ecosystem, leading to the extinction of an endemic herbivorous fish and the subsequent co-extinction of its obligate mutualistic plant. Following these events, the lake exhibits severe year-to-year fluctuations in total biomass. Based on the Rivet Popper Hypothesis and Tilman’s diversity-stability principles, which of the following statements regarding this ecosystem's collapse is INCORRECT?
Options
- A.
The extinction of the endemic herbivorous fish and its obligate plant acts as the loss of 'key rivets', critically compromising the ecosystem's functioning.
- B.
The severe year-to-year fluctuations in biomass indicate a loss of the ecosystem's ability to buffer against environmental stochasticity.
- C.
The drop in secondary productivity is exclusively attributed to the direct thermodynamic loss of the 10 percent energy transfer from the extinct herbivore.
- D.
The alien species invasion disrupted established niche partitioning, triggering a trophic cascading failure that destabilized the entire food web.
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
Decomposition Rate|Nutrient Cycling|Carbon Sequestration
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between thermodynamic energy flow and ecological network stability.
Students often misattribute ecosystem collapse solely to the loss of biomass/energy (10% law) from the extinct species.
However, the true driver of catastrophic secondary productivity loss is the structural unraveling of the food web (trophic cascade) and the loss of alternative energy pathways.
The absolute word 'exclusively' in Option C serves as the classic NEET 'Not/Except' trap.
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 |