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Question #46638
The Question
In a temperate lake ecosystem, zooplankton enter diapause during harsh winters. Concurrently, low temperatures severely retard the microbial decomposition of accumulated detritus. Upon the sudden onset of spring, zooplankton break diapause but experience a massive population crash. Which of the following best explains this phenomenon based on ecosystem dynamics?
Options
- A.
Zooplankton are unable to transition from the Grazing Food Chain (GFC) to the Detritus Food Chain (DFC) to directly consume the accumulated detritus.
- B.
Delayed mineralization in the DFC creates an inorganic nutrient bottleneck, preventing phytoplankton blooms and causing zooplankton starvation.
- C.
Accelerated humification during winter traps all available dissolved oxygen, leading to hypoxic conditions that kill the emerging zooplankton.
- D.
The sudden increase in temperature causes rapid catabolism by decomposers, which competitively excludes zooplankton from available organic nutrients.
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
Ectothermy|Metabolic Rates|Spatial Dispersion
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: This question tests the synthesis of 'Diapause' (Organisms & Populations) and 'Decomposition/Nutrient Cycling' (Ecosystem).
The trap relies on students failing to recognize the temporal dependency of the Grazing Food Chain on the Detritus Food Chain.
A common misconception is that once favorable conditions return, all trophic levels instantly resume normal activity, ignoring the sequential bottleneck of microbial mineralization.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Organisms and Populations - Class 12 |
| Concept | Population Density Estimation (Mark-Recapture) |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |