Before You Begin
Question #46012
The Question
In a terrestrial ecosystem, environmental conditions shift such that the rate of humification drastically exceeds the rate of mineralization over a prolonged period. Which of the following accurately describes the systemic consequence on the ecosystem's nutrient cycling?
Options
- A.
The soil acts as a nutrient sink due to the accumulation of a colloidal, microbial-resistant amorphous substance, thereby limiting primary productivity.
- B.
The detritus food chain (DFC) becomes highly efficient as the accumulated humus provides an immediate, rich source of inorganic nutrients for producers.
- C.
Water-soluble inorganic nutrients rapidly precipitate into the lower soil horizons, causing systemic nutrient depletion through enhanced leaching.
- D.
The ecosystem experiences a surge in net primary productivity (NPP) because humification directly releases essential elements like nitrogen and phosphorus.
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|Nutrient Cycling Reservoirs|Detritus Food Chain Dominance
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often hold the misconception that because humus is 'good for soil fertility', an increase in humification automatically and immediately boosts plant productivity.
The trap lies in failing to distinguish between the 'storage' function of humification and the 'release' function of mineralization.
Without mineralization, humus acts as a recalcitrant nutrient sink, starving the ecosystem of bioavailable inorganic nutrients.
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 |