In bacterial photosynthesis,

Options

A. (a) PS I is present
B. (b) PS II is present who does work of PS (II)
C. (c) Both PS I and PS II present
D. (d) None of these are present

Answer

**Step-by-Step Solution:**

1. **Understanding Bacterial Photosynthesis**:
- Bacterial photosynthesis differs from plant photosynthesis. It primarily involves a simpler process known as cyclic phosphorylation.

2. **Identifying the Photosystem**:
- In bacterial photosynthesis, only Photosystem I (PS1) is involved. This is distinct from plants, which utilize both Photosystem I and Photosystem II (PS2).

3. **Electron Donors and Acceptors**:
- In bacterial photosynthesis, the electron donor is hydrogen sulfide (H2S), while the electron acceptor is NADP+, which gets reduced to NADPH. In contrast, plants use water (H2O) as the electron donor, releasing oxygen in the process.

4. **Location of Photosynthesis**:
- The process of bacterial photosynthesis occurs in structures called chlorosomes or chromatophores, unlike plants, which perform photosynthesis in chloroplasts.

5. **Examples of Bacteria**:
- An example of bacteria that perform photosynthesis is cyanobacteria, which synthesize their own food and energy through this process.

6. **Choosing the Correct Answer**:
- Given the options, since only PS1 is involved in bacterial photosynthesis, the correct answer is option A (PS1 is present). The other options (PS2, both PS1 and PS2, none) are incorrect.

**Final Answer**: The photosystem involved in bacterial photosynthesis is Photosystem I (PS1).

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