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Question #47610
The Question
If a terrestrial ecosystem dominated by plants experiences a prolonged environmental shift that significantly increases the oxygenase activity of RuBisCO, how will this biochemically impact the ecosystem's trophic dynamics?
Options
- A.
The cellular requirement of 18 ATP and 12 NADPH per hexose is bypassed, increasing Gross Primary Productivity (GPP) and expanding the number of trophic levels.
- B.
The metabolic 'tax' of photorespiration increases the ATP cost per net carbon fixed, thereby reducing Net Primary Productivity (NPP) and restricting the biomass available to primary consumers.
- C.
The release of during the photorespiratory pathway directly increases the photosynthetic quotient, allowing more energy to bypass Lindeman's 10% bottleneck.
- D.
RuBisCO's oxygenase activity generates supplementary ATP in the peroxisome, which compensates for respiratory losses (R) and maintains a constant Net Primary Productivity (NPP).
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
C3 Cycle Stoichiometry|Trophic Efficiency Limits|Ecosystem
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Bridging micro-level cellular biochemistry (C3 stoichiometry and photorespiration) with macro-level ecology (NPP and Lindeman's 10% law).
The common misconception is treating plant physiology and ecology as isolated units.
Students often memorize that photorespiration is 'wasteful' but fail to apply this 'waste' as an increase in respiratory loss (R) that directly shrinks the ecosystem's carrying capacity and trophic length.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Photosynthesis in Higher Plants - Class 11 |
| Concept | C3 Cycle Stoichiometry |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |