The archaebacteria of extreme saline habitat.

Options

A. are able to use chemical energy for food synthesis
B. are called halophiles
C. oxidise sulphur to sulphuric acid under aerobic conditions
D. are obligate anaerobes

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about archaebacteria that thrive in extreme saline habitats. We need to identify the correct term used to describe these organisms.

2. **Analyzing the Options**:
- **Option A**: "Are able to use chemical energy for photosynthesis." This option is incorrect because photosynthesis is primarily a process associated with plants and some bacteria that use light energy, not chemical energy.
- **Option B**: "Are called holophiles." This option is correct. Holophiles, or halophiles, are organisms that thrive in high-salt environments.
- **Option C**: "Oxidized sulphur to sulphuric acid under aerobic conditions." This option is incorrect as it does not pertain to archaebacteria in saline habitats.
- **Option D**: "Are called obligate anaerobes." This option is also incorrect. Obligate anaerobes are organisms that cannot survive in the presence of oxygen, which is not relevant to the question.

3. **Identifying the Correct Answer**: After analyzing the options, the correct answer is Option B, which states that archaebacteria of extreme saline habitats are called holophiles.

4. **Defining Halophiles**: Halophiles are extremophiles that thrive in environments with high concentrations of salt. The term "halophile" comes from Greek, meaning "salt-loving."

5. **Conclusion**: Therefore, the archaebacteria of extreme saline habitats are known as halophiles.

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