One of the following is not characteristic feature of cyanobacteria

Options

A. They form colonies
B. They are multicellular
C. They form blooms in water bodies
D. They can fix atmospheric nitrogen.

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: The question is about cyanobacteria, which are also known as blue-green algae.

2. **Understand Characteristics of Cyanobacteria**:
- Cyanobacteria are prokaryotic organisms.
- They are primarily unicellular but can form large colonies.
- They are capable of fixing atmospheric nitrogen using specialized cells called heterocysts.
- They can form algal blooms in water bodies, especially in polluted conditions.

3. **Analyze the Options**:
- **Option A**: They form colonies. (This is a characteristic feature of cyanobacteria.)
- **Option B**: They are multicellular. (This is NOT a characteristic feature of cyanobacteria, as they are primarily unicellular.)
- **Option C**: They form blooms in water bodies. (This is a characteristic feature of cyanobacteria.)
- **Option D**: They can fix atmospheric nitrogen. (This is a characteristic feature of cyanobacteria.)

4. **Conclusion**: The option that is NOT a characteristic feature of cyanobacteria is **Option B: They are multicellular**.

**Final Answer**: B) They are multicellular.

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