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Question #47580
The Question
In a pelagic marine ecosystem, the pyramid of biomass is typically inverted, with a small standing crop of phytoplankton supporting a much larger biomass of zooplankton and fishes. Which of the following statements regarding the ecological and physiological dynamics of this ecosystem is INCORRECT?
Options
- A.
Phytoplankton compensate for their low standing crop through a remarkably high mitotic index and rapid turnover rate.
- B.
The standing crop of producers, measured as the mass of living material at a specific given time, is lower than that of the primary consumers.
- C.
The inverted biomass pyramid indicates that the annual primary productivity of phytoplankton is lower than the secondary productivity of zooplankton.
- D.
Despite the inverted biomass pyramid, the energy pyramid remains strictly upright due to the continuous and massive energy flow from the rapidly dividing producers.
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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
Phytoplankton|Zooplankton|Primary Productivity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Distinguishing between 'Standing Crop' (a static snapshot of biomass) and 'Productivity' (a kinetic rate of energy/biomass generation).
Students often erroneously assume that an inverted biomass pyramid implies inverted productivity or energy flow.
The trap exploits the confusion between the low static mass of phytoplankton and their massive, rapid rate of cell division (high turnover) which ensures primary productivity remains higher than secondary productivity.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | Mitotic Index Implications |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |