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Question #47639
The Question
A novel herbicide specifically blocks the resonance energy transfer from accessory pigments to the reaction center (P680) within the Light Harvesting Complex (LHC) of Photosystem II. Which of the following represents the most accurate physiological consequence of this inhibition?
Options
- A.
Cessation of water photolysis, resulting in a relative increase in thylakoid luminal pH and subsequent inactivation of the Oxygen Evolving Complex.
- B.
P680 undergoes continuous photo-oxidation by directly absorbing light, leading to excessive acidification of the thylakoid lumen.
- C.
NADP+ reduction continues uninterrupted on the luminal side of the thylakoid membrane, while ATP synthesis completely halts.
- D.
Cyclic photophosphorylation via Photosystem I takes over the photolysis of water to maintain the transmembrane proton gradient.
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
Rubisco|Chlorophyll-a|Enzyme Activation Energy
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that 'P680 splits water' but fail to connect the thermodynamic dependency of the OEC on the continuous generation of P680+ via the LHC's energy funneling.
Furthermore, this tests the location-specific pH dynamics (lumen acidification via photolysis) and the 'Not/Except' style trap of confusing the stromal vs. luminal side for NADP+ reduction.
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 |