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Question #47598
The Question
In the Kranz anatomy of plants, bundle sheath cells exhibit specific structural and physiological adaptations to maximize carbon fixation. Which of the following statements regarding the bundle sheath chloroplasts is INCORRECT?
Options
- A.
They possess agranal chloroplasts that lack the water-splitting complex, thereby preventing oxygen evolution.
- B.
They rely on cyclic photophosphorylation to generate both the ATP and NADPH required to drive the cycle.
- C.
They exhibit high RuBisCO activity due to a high intracellular concentration provided by malate decarboxylation.
- D.
They lack Photosystem II activity, making cyclic electron flow a metabolic necessity rather than a backup mechanism.
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
Cyclic Photophosphorylation Pathways|Kranz Anatomy Adaptations
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often memorize that bundle sheath cells perform cyclic photophosphorylation but forget the biochemical limitations of this process (it produces only ATP, not NADPH).
The trap exploits the assumption that since the Calvin cycle requires both ATP and NADPH, the light reactions in the BSC must provide both, ignoring the crucial role of the acid (malate) shuttle in delivering reducing power (NADPH) from the mesophyll.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Photosynthesis in Higher Plants - Class 11 |
| Concept | Cyclic Photophosphorylation Pathways |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |