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Question #46011
The Question
In a terrestrial ecosystem, prolonged waterlogging creates severe anaerobic conditions in the soil. Based on the NCERT principles of decomposition, which of the following represents the most accurate sequence of ecological consequences leading to a decline in primary productivity?
Options
- A.
Inhibition of detritivores -> Accelerated leaching of water-soluble nutrients -> Rapid mineralization -> Nutrient toxicity
- B.
Inhibition of aerobic saprotrophs -> Accumulation of refractory organic matter (humus) -> Halting of mineralization -> Nutrient immobilization
- C.
Acceleration of anaerobic catabolism -> Rapid humification -> Premature release of inorganic ions -> Root osmotic stress
- D.
Enhanced fragmentation by earthworms -> Inhibition of humification -> Direct mineralization -> Depletion of soil organic carbon
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
Humification vs Mineralization|Decomposition Rate Modifiers|Nutrient Immobility
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often confuse 'moist soil' (which favors decomposition) with 'waterlogged soil' (which creates anaerobiosis and inhibits it).
Furthermore, students frequently fail to link the inhibition of mineralization directly to nutrient immobilization.
The trap relies on the misconception that anaerobic bacteria will simply take over and maintain the nutrient cycle, whereas ecologically, anaerobiosis acts as a severe bottleneck that uncouples humification from mineralization, leading to organic build-up (e.g., peat bogs) and plant starvation.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Ecosystem - Class 12 |
| Concept | Humification vs Mineralization |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |