Cyclic Photophosphorylation links to

Options

A. PS-II
B. PS-I
C. dark reaction
D. Both (1) & (2)

Answer

### Step-by-Step Solution:

1. **Understanding Cyclic Photophosphorylation**:
- Cyclic photophosphorylation is a process that occurs during the light reactions of photosynthesis. It primarily involves the photosystem I (PS1).

2. **Differentiating Between Photophosphorylation Types**:
- There are two types of photophosphorylation: cyclic and non-cyclic.
- Non-cyclic photophosphorylation involves both PS1 and PS2, while cyclic photophosphorylation involves only PS1.

3. **Identifying the Components**:
- In cyclic photophosphorylation, electrons are excited in PS1 and are cycled back to the same photosystem after passing through an electron transport chain, which leads to the production of ATP.

4. **Evaluating the Options**:
- **Option A (PS2)**: This is not involved in cyclic photophosphorylation, so it can be eliminated.
- **Option B (PS1)**: This is the correct answer, as cyclic photophosphorylation directly involves PS1.
- **Option C (Dark Reaction)**: The dark reactions (Calvin cycle) do not occur during cyclic photophosphorylation, so this option can also be eliminated.
- **Option D (Both 1 and 2)**: This option is incorrect because cyclic photophosphorylation does not involve PS2.

5. **Final Conclusion**:
- The correct answer is **Option B (PS1)**, as cyclic photophosphorylation links specifically to photosystem I.