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Question #47640
The Question
A hypothetical mutation in a marine phytoplankton community results in the complete loss of all accessory pigments (carotenoids, xanthophylls, and chlorophyll-b), leaving only Chlorophyll-a functional. Which of the following would be the most direct and significant ecological consequence of this mutation on the marine ecosystem?
Options
- A.
The action spectrum of photosynthesis will perfectly overlap with the absorption spectrum of Chlorophyll-a, leading to an increase in the number of trophic levels due to higher quantum yield.
- B.
The Gross Primary Productivity (GPP) will drastically decrease due to the inability to harvest light in the 500-600 nm spectrum, resulting in a thermodynamic truncation of the food chain.
- C.
The phytoplankton will migrate to deeper waters to avoid photo-oxidation, causing the pyramid of energy to become inverted due to altered energy flux.
- D.
The Net Primary Productivity (NPP) will remain unaffected because Chlorophyll-a is the primary reaction center, but the 10% energy transfer law will be violated.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Comparative_Analysis
Sharpen your ability to evaluate multiple scenarios and distinguish between competing potential answers.
Concepts Behind This Question
Chlorophyll-a|Trophic Efficiency|Ecosystem Productivity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'Chlorophyll-a is the main pigment' and might assume photosynthesis can proceed efficiently without accessory pigments.
This question tests the ability to link the molecular function of accessory pigments (broadening the action spectrum) to macro-ecological concepts like GPP, NPP, and the thermodynamic limits of food chain length.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Photosynthesis in Higher Plants - Class 11 |
| Concept | Chlorophyll-a vs Accessory Pigments |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |