Question

Which of the following statements is incorrect

• A. Cyclic photophosphorylation involves both PS I and PS II.
• B. Both ATP and NADPH+H⁺ are synthesized during non-cyclic photophosphorylation
• C. Stroma lamellae have PS I only and lack NADP reductase
• D. Grana lamellae have both PS I and PS II

Answer 1

The Correct Option is A

To determine which statement is incorrect, let's analyze each option based on photosynthesis concepts:

1. Cyclic photophosphorylation involves both PS I and PS II.
   • Analysis: Cyclic photophosphorylation involves only photosystem I (PS I). It does not involve photosystem II (PS II). In cyclic photophosphorylation, electrons are cycled back to PS I, and only ATP is produced, not NADPH.
   • Conclusion: This statement is incorrect because PS II is not involved in cyclic photophosphorylation.
2. Both ATP and NADPH+H⁺ are synthesized during non-cyclic photophosphorylation.
   • Analysis: Non-cyclic photophosphorylation involves both PS I and PS II and leads to the production of ATP and NADPH. Electrons are transferred from water to NADP⁺, synthesizing NADPH along with ATP generation through photophosphorylation.
   • Conclusion: This statement is correct.
3. Stroma lamellae have PS I only and lack NADP reductase.
   • Analysis: Stroma lamellae contain PS I but not PS II, aligning with their role in cyclic photophosphorylation, and they do lack NADP reductase, which is part of the non-cyclic electron transport chain.
   • Conclusion: This statement is correct.
4. Grana lamellae have both PS I and PS II.
   • Analysis: Grana lamellae have both PS I and PS II. These structures are responsible for non-cyclic photophosphorylation, which involves both photosystems to generate ATP and NADPH.
   • Conclusion: This statement is correct.

After evaluating the options, it is clear that the incorrect statement is: "Cyclic photophosphorylation involves both PS I and PS II."