Pigment molecule present at reaction centre of PS-I and PS-II respectively are

Options

A. (a) Chl-a and chl-a
B. (b) chl-a and chl-b
C. (c) chl-b and chl-a
D. (d) chl-b and chl-b

Answer

To answer the question regarding the pigment molecules present at the reaction center of Photosystem I (PS-I) and Photosystem II (PS-II), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosystems**:
- Photosystems are complexes in plants that play a crucial role in the process of photosynthesis. There are two main types: Photosystem I (PS-I) and Photosystem II (PS-II).

2. **Identifying the Pigments**:
- The primary pigment involved in photosynthesis is chlorophyll. There are different types of chlorophyll, but the most significant for photosystems are chlorophyll A and chlorophyll B.

3. **Pigment in PS-I**:
- The reaction center of Photosystem I primarily contains chlorophyll A. This pigment is essential for capturing light energy and converting it into chemical energy.

4. **Pigment in PS-II**:
- Similarly, the reaction center of Photosystem II also contains chlorophyll A. It is involved in the initial steps of photosynthesis, where light energy is absorbed and used to split water molecules, releasing oxygen.

5. **Conclusion**:
- Therefore, the pigment molecules present at the reaction centers of PS-I and PS-II are both chlorophyll A.

### Final Answer:
The pigment molecules present at the reaction center of PS-I and PS-II respectively are **Chlorophyll A** (for both).