Which is sensitive to longer wavelengths of light

Options

A. `PS` II
B. `PS` I
C. Phosphorylation
D. Photolysis.

Answer

**Step-by-Step Solution:**

1. **Understanding Wavelengths of Light:**
- In the visible spectrum, light can be categorized by its wavelength. Longer wavelengths correspond to red light, while shorter wavelengths correspond to blue and green light.

2. **Identifying the Photosystems:**
- Photosynthesis involves two main photosystems: Photosystem I (PSI) and Photosystem II (PSII). Each photosystem has a specific range of wavelengths it absorbs.

3. **Absorption Characteristics:**
- Photosystem I absorbs light at approximately 700 nanometers (nm), which is in the red region of the spectrum.
- Photosystem II absorbs light at around 680 nm, which is slightly shorter than the wavelength absorbed by PSI.

4. **Determining Sensitivity to Longer Wavelengths:**
- Since Photosystem I absorbs light at a longer wavelength (700 nm) compared to Photosystem II (680 nm), it is more sensitive to longer wavelengths of light.

5. **Conclusion:**
- Based on the absorption characteristics, Photosystem I is the photosystem that is sensitive to longer wavelengths of light.

**Final Answer:**
- Photosystem I is sensitive to longer wavelengths of light.

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