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Question #47588
The Question
An artificial terrestrial ecosystem is subjected to a continuous light source emitting exclusively wavelengths beyond 680 nm (far-red light). Based on the principles of plant physiology and ecosystem energy flow, which of the following statements is INCORRECT regarding the downstream ecological consequences?
Options
- A.
The quantum yield of the producers will experience a sharp decline known as the Red Drop, severely limiting Gross Primary Productivity (GPP).
- B.
The absence of shorter wavelengths prevents the Emerson enhancement effect, halting non-cyclic electron transport and the generation of NADPH.
- C.
The Net Primary Productivity (NPP) will eventually become negative as the producers' respiratory losses (R) exceed the restricted GPP.
- D.
The standing crop of primary consumers will be sustained because cyclic photophosphorylation continues to generate ATP for the producers.
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
Standing_Crop|10_Percent_Law|Primary_Productivity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Bridging the micro-level biochemical requirement of NADPH for carbon fixation with the macro-level ecological concept of NPP and standing crop.
Common Misconception: Students often assume that if any photophosphorylation (like cyclic) is occurring, the plant is producing energy and can sustain an ecosystem.
They fail to realize that without PS II, there is no NADPH, no carbon fixation, and thus zero NPP (biomass) to transfer to the next trophic level according to the 10% law.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Photosynthesis in Higher Plants - Class 11 |
| Concept | Red Drop and Emerson Enhancement Effect |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |