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Question #46640
The Question
In a marine ecosystem, the pyramid of biomass is inverted, presenting a potential paradox for the Optimal Foraging Theory: how do primary consumers (zooplankton) avoid expending more energy searching for sparse prey than they gain? The resolution to this energetic trap lies in the precise distinction between specific ecological parameters. Which of the following accurately explains how this ecosystem sustains a higher consumer biomass?
Options
- A.
The standing crop of phytoplankton is low, but their Net Primary Productivity (NPP) is exceptionally low compared to their Gross Primary Productivity (GPP), maximizing energy transfer.
- B.
The standing crop of phytoplankton is low, but their rapid turnover rate ensures a continuous high rate of replacement, sustaining the higher biomass of zooplankton.
- C.
The ecosystem relies on an inverted pyramid of energy, where the energy accumulated at the primary consumer level exceeds that of the primary producers.
- D.
Zooplankton decrease their foraging energy expenditure by relying primarily on the Detritus Food Chain (DFC), which is the major conduit of energy flow in aquatic ecosystems.
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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
MacArthur’s Warblers|Competitive Exclusion Principle|Invasive Specialists
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between 'Standing Crop' (a static measurement of biomass at a specific time) and 'Turnover Rate/Productivity' (a dynamic rate of replacement).
Students often falsely equate a low standing crop with low overall energy availability, leading them to incorrectly assume the energy pyramid must also be inverted or that the ecosystem must rely on alternative food chains.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Resource Partitioning (MacArthur’s Warblers) |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |