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Question #46124
The Question
A researcher introduces freshwater sponges (Spongilla) into an aeration tank containing a high concentration of activated sludge to test their efficacy as auxiliary bio-filters. Within days, the sponges exhibit a complete cessation of their water canal system and die of starvation. What is the primary physiological cause of this 'regulatory failure'?
Options
- A.
The high biochemical oxygen demand (BOD) of the sludge induces anaerobic respiration in choanocytes, halting intracellular digestion.
- B.
The dense microbial flocs physically clog the ostia and the microvilli collars of choanocytes, preventing flagellar beat-driven micro-currents.
- C.
The excessive microbial load reverses the flow of water, causing effluent to enter through the osculum and exit via the ostia.
- D.
The fungal filaments in the activated sludge paralyze the flagella of the pinacocytes lining the spongocoel.
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
Choanocytes|Activated Sludge Inoculum|Suspension Feeding
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Integrating the anatomical limits of Poriferan filter-feeding (choanocyte microvilli and ostia size) with the ecological characteristics of activated sludge (dense microbial flocs).
The trap relies on the misconception that 'more microbes equal more food' for a filter feeder, ignoring the mechanical threshold of the aquiferous system.
It also tests precise anatomical locations (choanocytes vs. pinacocytes).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Porifera Canal System dynamics |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |