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Question #46673
The Question
In a shallow lake undergoing hydrarch succession, ecological analysis reveals a massive accumulation of highly refractory detritus (rich in lignin and chitin) at the benthic zone, accompanied by severe anaerobiosis. Which of the following best explains the consequence of this condition on the successional progression?
Options
- A.
Accelerated mineralization of the detritus will trigger sudden eutrophication, reverting the sere back to the pioneer phytoplankton stage.
- B.
Severe nutrient immobilization within the detritus will stall pedogenesis, preventing the establishment of the marsh-meadow and scrub stages.
- C.
The accumulation of undecomposed organic matter will increase the water depth, preventing the rooting of emergent macrophytes like Typha.
- D.
The detritus food chain (DFC) will completely replace the grazing food chain (GFC), establishing a climax community dominated by saprotrophs.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Nutrient_Immobility|Ecological_Succession_Climax|Hydrarch_vs_Xerarch_Convergence
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize the sequence of hydrarch succession as an automatic, time-driven progression.
This question forces the integration of two distinct NCERT concepts from the 'Ecosystem' chapter: the stages of succession and the factors affecting decomposition.
The common misconception is assuming that any detritus accumulation automatically equals fertile soil formation, ignoring the thermodynamic bottleneck of nutrient immobilization caused by refractory biochemicals (lignin/chitin).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Trophic Efficiency Limits |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |