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Question #46016
The Question
In a waterlogged wetland ecosystem, an ecologist notes that despite a massive continuous input of detritus, the availability of inorganic nutrients like nitrogen and phosphorus for plant uptake remains critically low. Soil analysis reveals a massive build-up of a dark-colored, amorphous substance. Which of the following statements correctly identifies the physiological bottleneck in this ecosystem's nutrient cycle?
Options
- A.
The anaerobic environment has accelerated the catabolism of detritus, causing rapid leaching of water-soluble inorganic nutrients beyond the root zone.
- B.
Anaerobiosis has inhibited complete decomposition, leading to the accumulation of colloidal humus while severely restricting mineralization, thereby immobilizing nutrients.
- C.
The detritus is rich in lignin and chitin, which directly promotes rapid mineralization over humification, depleting the soil of organic reservoirs.
- D.
The accumulated dark amorphous substance is highly susceptible to microbial action, leading to rapid nutrient depletion via denitrification rather than mineralization.
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
Detritus Food Chain Dominance | Humification vs Mineralization | Nutrient Immobility
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often harbor the misconception that high organic matter (humus) automatically equates to high immediate soil fertility.
They fail to distinguish between the 'reservoir' function of humus (humification) and the 'release' function (mineralization).
The trap lies in recognizing that without aerobic microbes to perform mineralization, nutrients remain immobilized in the colloidal humus, rendering the soil functionally infertile for immediate plant uptake despite high detritus input.
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 |