Which of the following are archaebacteria ?

Options

A. Green suphur bacteria
B. Thermoplasma
C. Pseudomonas
D. Chalmydias

Answer

To determine which of the given options are archaebacteria, we need to analyze each option based on their classification.

### Step-by-Step Solution:

1. **Understanding Archaebacteria**:
- Archaebacteria are a group of microorganisms that are distinct from bacteria and eukaryotes. They are known for their ability to thrive in extreme environments, such as high temperatures and acidic conditions.

2. **Analyzing Option A: Green Sulphur Bacteria**:
- Green sulphur bacteria are a type of bacteria that are photoautotrophic and anaerobic. They are not classified as archaebacteria; instead, they belong to the domain of bacteria.
- **Conclusion**: Not archaebacteria.

3. **Analyzing Option B: Thermoplasma**:
- Thermoplasma is a genus of the family Thermoplasmataceae, which is part of the Archaea domain. These organisms thrive in acidic and high-temperature environments.
- **Conclusion**: This is archaebacteria.

4. **Analyzing Option C: Pseudomonas**:
- Pseudomonas is a genus of gram-negative bacteria that is part of the Proteobacteria phylum. It is not classified as archaebacteria.
- **Conclusion**: Not archaebacteria.

5. **Analyzing Option D: Chlamydia**:
- Chlamydia is a genus of bacteria that causes various infections, including trachoma. It belongs to the family Chlamydiaceae and is not classified as archaebacteria.
- **Conclusion**: Not archaebacteria.

### Final Answer:
- The only option that is classified as archaebacteria is **Option B: Thermoplasma**.