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Question #46654
The Question
In a marine ecosystem, the pyramid of biomass is typically inverted, with the standing crop of phytoplankton being significantly smaller than that of zooplankton. Despite this, the ecosystem remains energetically stable. Which of the following ecological principles best explains this apparent paradox?
Options
- A.
Phytoplankton exhibit a rapid turnover rate, meaning their Gross Primary Productivity (GPP) as a rate of energy flow is high, even though their measured standing crop at any given time is low.
- B.
The Net Primary Productivity (NPP) of phytoplankton is lower than the respiratory losses of zooplankton, but the energy deficit is supplemented by the detritus food chain.
- C.
The pyramid of energy in this specific aquatic ecosystem is also inverted, allowing a smaller biomass of producers to support a larger biomass of primary consumers.
- D.
Phytoplankton possess a high standing crop but exceptionally low Gross Primary Productivity (GPP), causing a delayed but rapid depletion of the producer trophic level.
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
Ecotone and Edge Effect|Productivity Ratios|Decomposition Rate Modifiers
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between a 'pool' (Standing Crop/Biomass) and a 'flux' (Productivity/Rate).
The common misconception is assuming that an inverted biomass pyramid implies low productivity or an inverted energy pyramid.
Students often fail to account for the rapid turnover rate (short generation time) of phytoplankton, which allows a small standing mass to sustain a massive energetic throughput.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Ecotone and Edge Effect |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |