What is true for Mycoplasma?

Options

A. They completely lack cell wall
B. They are the smallest living organisms known
C. They can survive without oxygen
D. All the above

Answer

### Step-by-Step Solution:

1. **Understanding Mycoplasma**:
- Mycoplasma are a genus of bacteria that belong to the kingdom Monera. They are known to be the smallest living organisms.

2. **Characteristics of Mycoplasma**:
- **Lack of Cell Wall**: Mycoplasma completely lack a cell wall, which distinguishes them from most other bacteria. This absence of a cell wall means they do not have a definite shape.
- **Smallest Living Organisms**: They are recognized as the smallest known living organisms, which contributes to their unique classification.
- **Anaerobic Survival**: Mycoplasma can survive without oxygen, making them capable of living in anaerobic environments.

3. **Evaluating the Options**:
- **Option A**: They completely lack a cell wall. (True)
- **Option B**: They are the smallest living organisms known. (True)
- **Option C**: They can survive without oxygen. (True)
- **Option D**: All of the above. (True)

4. **Conclusion**:
- Since all the statements about Mycoplasma are true, the correct answer is **Option D: All of the above**.