Photosystem has main light harvesting pigments

Options

A. (a) Chlorophyll a-660, chl a-670, chl a-680, chl a-690, chl a-700
B. (b) Chlorophyll a-660, chl b, chl a-700, chl a-800 and carotenoid
C. (b) Chlorophyll a-680, chl a-685, chl a-695 and xanthophyll
D. (d) Chlorophyll a-700, chl a-800, chl-b, chl a-685 and phycobilins.

Answer

### Step-by-Step Solution:

1. **Understanding Photosystems**:
- Photosystems are complexes in chloroplasts that play a crucial role in photosynthesis. There are two main types: Photosystem I (PSI) and Photosystem II (PSII).

2. **Identifying the Main Pigments**:
- The primary pigments involved in these photosystems are chlorophyll a, chlorophyll b, and carotenoids.
- Chlorophyll a is the main pigment that participates directly in the light reactions of photosynthesis.

3. **Wavelength Absorption**:
- Chlorophyll a absorbs light primarily in the range of 660 nm to 680 nm (red light) and also has some absorption in the near-infrared region (around 700 nm).
- Chlorophyll b absorbs light in the range of approximately 480 nm to 680 nm (blue and red light).
- Carotenoids absorb light in the blue and green wavelengths, contributing to the light-harvesting process.

4. **Location of Photosystems**:
- Both photosystems are located in the thylakoid membranes of chloroplasts, which are the organelles responsible for photosynthesis in plant cells.

5. **Conclusion**:
- The main light-harvesting pigments in photosystems are chlorophyll a, chlorophyll b, and carotenoids. Chlorophyll a is the most critical pigment for the photosynthetic process.

### Final Answer:
The main light-harvesting pigments in photosystems are chlorophyll a, chlorophyll b, and carotenoids.

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