Which of the following statements is incorrect?

The correct option (the incorrect statement) is: Cyclic photophosphorylation involves both PS I and PS II.

Let us analyze each statement step-by-step to understand why this statement is incorrect and why the other options are correct biology facts:

1. Analysis of Cyclic Photophosphorylation:
Cyclic photophosphorylation occurs when only Photosystem I (PS I) is functional. The electron expelled from the reaction center of PS I (P700) passes through a series of electron carriers and eventually cycles back to the same reaction center (P700). Photosystem II (PS II) is not involved in this process. Because PS II is not active here, there is no photolysis of water and no synthesis of ${\text{NADPH + H}}_{\mathrm{+}}$; only ATP is produced. Therefore, the statement claiming that cyclic photophosphorylation involves both PS I and PS II is false (incorrect).

2. Analysis of Grana Lamellae:
The grana lamellae (thylakoids of grana) possess both Photosystem I (PS I) and Photosystem II (PS II). Thus, the statement "Grana lamellae have both PS I and PS II" is correct.

3. Analysis of Non-Cyclic Photophosphorylation:
During non-cyclic photophosphorylation (also known as the Z-scheme), electrons flow from water through PS II to PS I, and finally to ${\text{NADP}}^{\mathrm{+}}$. This pathway involves both photosystems and results in the synthesis of both ATP and ${\text{NADPH + H}}_{\mathrm{+}}$. Thus, the statement "Both ATP and NADPH + H⁺ are synthesized during non-cyclic photophosphorylation" is correct.

4. Analysis of Stroma Lamellae:
The stroma lamellae (membranes connecting the grana) lack Photosystem II (PS II) and the enzyme NADP reductase. They only contain Photosystem I (PS I). Therefore, the statement "Stroma lamellae have PS I only and lack NADP reductase" is correct.