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Question #46017
The Question
In a pelagic aquatic ecosystem exhibiting an inverted pyramid of biomass, a chemical spill selectively inhibits the benthic decomposers and detritivores. Which of the following best explains why this ecosystem will experience a much faster systemic collapse compared to a mature terrestrial forest under the same chemical stress?
Options
- A.
The primary producers possess a low standing crop and high turnover rate, making the ecosystem critically dependent on the DFC for rapid nutrient regeneration.
- B.
The Detritus Food Chain (DFC) is the major conduit for energy flow in aquatic ecosystems, and its inhibition halts all energy transfer to higher trophic levels.
- C.
Phytoplankton depend directly on the DFC for their energy requirements, and inhibiting decomposers immediately starves the producers of ATP.
- D.
The inverted biomass pyramid dictates that top consumers hold the maximum energy, which rapidly dissipates without detritivore-mediated energy recycling.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Detritus Food Chain Dominance | Ecological Succession Climax | Inverted Biomass Pyramids
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between Biomass, Energy Flow, and Nutrient Cycling.
The primary trap is confusing the roles of the GFC and DFC in different ecosystems.
Students must recall the NCERT fact that GFC dominates aquatic energy flow, while DFC dominates terrestrial energy flow.
However, they must synthesize this with the fact that DFC's role in nutrient cycling is universally critical, and a low standing crop (characteristic of inverted biomass pyramids) makes an ecosystem hyper-vulnerable to disruptions in nutrient regeneration.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Detritus Food Chain Dominance |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |