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Question #47568
The Question
A municipal sewage plant discharges primary effluent directly into a freshwater lake, bypassing secondary biological treatment. Meanwhile, a coastal aquaculture facility commercially cultivates specific marine algae. Which of the following statements correctly distinguishes the resulting ecological phenomenon in the lake from the economic utility of the coastal algae?
Options
- A.
The lake will develop a bloom of planktonic Cyanophyceae and Chlorophyceae due to high organic loading, whereas the coastal facility cultivates macroscopic Phaeophyceae and Rhodophyceae for algin and carrageen extraction.
- B.
The primary effluent will cause a massive proliferation of Gracilaria in the lake, whereas the coastal facility harvests planktonic dinoflagellates for commercial hydrocolloids.
- C.
Bypassing secondary treatment prevents the release of nitrates and phosphates, thereby inhibiting algal blooms in the lake, while the coastal facility relies on these nutrients to produce agar from brown algae.
- D.
The lake will experience a sharp decrease in Biochemical Oxygen Demand (BOD) due to the photosynthetic activity of the resulting algal bloom, similar to the oxygenation provided by commercially grown Porphyra.
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
Chlorophyceae|Flagella|Centrosome|Cytoskeleton
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: The question tests the student's ability to compartmentalize 'Algae' across different NCERT chapters.
It requires distinguishing between freshwater, bloom-forming microalgae (Environmental Issues) driven by anthropogenic nutrient loading, and marine, macroscopic algae (Plant Kingdom) cultivated for specific economic products.
A common misconception targeted in Option D is the belief that algal blooms permanently decrease BOD because they are photosynthetic; students often forget the severe DO depletion that occurs during the decomposition phase of the bloom.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Chlorophyceae Flagellar Insertion |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |