The wavelength of light absorbed by reaction centre of PS-II is

Options

A. 640 nm
B. 680 nm
C. 720 nm
D. 940 nm

Answer

To determine the wavelength of light absorbed by the reaction center of Photosystem II (PS-II), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components of Photosynthesis**:
- Photosynthesis occurs in two main stages: light-dependent reactions and light-independent reactions. The light-dependent reactions involve two photosystems: Photosystem I (PS-I) and Photosystem II (PS-II).

2. **Identify the Function of Photosystems**:
- Both PS-I and PS-II play crucial roles in capturing light energy and converting it into chemical energy. They are located in the thylakoid membranes of chloroplasts.

3. **Know the Specific Wavelengths**:
- Each photosystem has a specific pigment that absorbs light at particular wavelengths.
- PS-I is associated with the pigment P700, which absorbs light most efficiently at 700 nanometers.
- PS-II is associated with the pigment P680, which absorbs light most efficiently at 680 nanometers.

4. **Evaluate the Options**:
- The question provides multiple-choice options: 640 nm, 680 nm, 720 nm, and 940 nm.
- Since we know that PS-II absorbs light at 680 nm, we can eliminate the other options.

5. **Select the Correct Answer**:
- The correct answer is 680 nanometers, as it is the wavelength absorbed by the reaction center of PS-II.

### Final Answer:
The wavelength of light absorbed by the reaction center of Photosystem II (PS-II) is **680 nanometers**.

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