Which of the following are found in extreme saline conditions?

Options

A. Archaebacteria
B. Eubacteria
C. Cyanobacteria
D. Mycobacteria

Answer

**Step-by-Step Solution:**

1. **Identify the Options**: The question provides four options: Archaeobacteria, Eubacteria, Cyanobacteria, and Mycobacteria.

2. **Understand the Classification**: All these options fall under the kingdom Monera, which includes all types of bacteria. However, they have different characteristics and adaptations.

3. **Focus on Archaeobacteria**: Among these, Archaeobacteria are known for their unique ability to thrive in extreme environments. Their cell wall structure is different from that of other bacteria, which allows them to survive in harsh conditions.

4. **Categories of Archaeobacteria**: Archaeobacteria can be divided into three main categories:
- **Halophiles**: These organisms thrive in high-salinity environments, such as salt lakes and salt mines.
- **Thermoacidophiles**: These are found in hot springs and acidic environments.
- **Methanogens**: These are found in anaerobic environments, such as the guts of ruminant animals.

5. **Identify the Correct Answer**: Since the question specifically asks about organisms found in extreme saline conditions, the correct answer is **Archaeobacteria**, specifically the Halophiles group.

6. **Conclusion**: Therefore, the answer to the question "Which of the following are found in extreme saline conditions?" is **A. Archaeobacteria**.

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