Archaebacteria shows similarity with Mycoplasma in having :

Options

A. pigmented membrane
B. DNA associated with histone protein
C. rigid cell wall
D. `70S` ribosomes

Answer

**Step-by-Step Solution:**

1. **Understanding the Organisms:**
- Archaebacteria and Mycoplasma are both types of microorganisms. Archaebacteria are a group of prokaryotes that are distinct from bacteria and eukaryotes, while Mycoplasma are a type of bacteria that are known for their lack of a cell wall.

2. **Identifying Key Characteristics:**
- Mycoplasma are unique because they do not have a rigid cell wall, which is a common feature in most bacteria. Instead, they have a flexible membrane.
- Archaebacteria, on the other hand, have unique membrane lipids and can also lack a cell wall in some species.

3. **Ribosomal Structure:**
- Both Archaebacteria and Mycoplasma possess 70S ribosomes. This is a significant similarity, as the ribosomal structure plays a crucial role in protein synthesis.
- The 70S ribosome is composed of two subunits: 50S and 30S.

4. **Evaluating Other Options:**
- The question mentions other characteristics such as "pigmented membrane," "DNA associated with stone proteins," and "rigid cell wall."
- Archaebacteria do not have a rigid cell wall like typical bacteria, and Mycoplasma lack a cell wall entirely.
- The association of DNA with stone proteins is more characteristic of eukaryotic cells, where DNA is wrapped around histone proteins.

5. **Conclusion:**
- The only correct similarity between Archaebacteria and Mycoplasma is the presence of 70S ribosomes.

**Final Answer:**
- Archaebacteria shows similarity with Mycoplasma in having 70S ribosomes.

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