The characteristic pigment of Cyanobacteria is

Options

A. chlorophyll a
B. fucoxanthin
C. phycocyanin
D. chlorophyll d

Answer

To solve the question regarding the characteristic pigment of Cyanobacteria, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organism**: The question asks about Cyanobacteria, which are a group of photosynthetic bacteria often referred to as blue-green algae.

2. **Understand the Pigments**: Cyanobacteria contain various pigments that allow them to perform photosynthesis. The main pigments to consider are:
- Chlorophyll A
- Phycocyanin
- Chlorophyll D
- Fucosanthin

3. **Evaluate Each Option**:
- **Option A: Chlorophyll A**: This is a primary pigment found in Cyanobacteria and is essential for photosynthesis. It is the most characteristic pigment of Cyanobacteria.
- **Option B: Fucosanthin**: This pigment is found in brown algae, not in Cyanobacteria, making this option incorrect.
- **Option C: Phycocyanin**: This is a blue pigment found in Cyanobacteria, but it is not the primary or characteristic pigment.
- **Option D: Chlorophyll D**: This pigment is primarily found in marine red algae, making it an incorrect choice for Cyanobacteria.

4. **Conclusion**: Based on the evaluation, the characteristic pigment of Cyanobacteria is **Chlorophyll A**.

### Final Answer:
The characteristic pigment of Cyanobacteria is **Chlorophyll A**.

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