Which is not an accessory pigment

Options

A. Carotene
B. Xanthophyll
C. Chlorophyll a
D. Chlorophyll b.

Answer

To determine which pigment is not an accessory pigment, we need to understand the roles of different pigments involved in photosynthesis.

### Step-by-Step Solution:

1. **Identify the Types of Pigments**: In photosynthesis, pigments are classified into two main categories: primary pigments and accessory pigments. The primary pigment is responsible for the initial capture of light energy.

2. **Recognize the Primary Pigment**: The primary pigment in photosynthesis is **chlorophyll A**. It plays a crucial role in the light-dependent reactions of photosynthesis by absorbing light energy.

3. **Identify Accessory Pigments**: Accessory pigments assist in capturing light energy and include:
- **Chlorophyll B**: This pigment complements chlorophyll A by absorbing light in different wavelengths.
- **Carotenoids**: This group includes pigments like **carotene** and **xanthophyll**, which also help in light absorption.

4. **Analyze the Options**: The question provides the following options:
- Carotene
- Xanthophyll
- Chlorophyll A
- Chlorophyll B

5. **Determine the Correct Answer**: Among the options, **chlorophyll A** is the only pigment that is not classified as an accessory pigment. Instead, it is the primary pigment responsible for photosynthesis.

### Conclusion:
The pigment that is not an accessory pigment is **chlorophyll A**.

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