The most primitive of monerans are

Options

A. Rickettsiae
B. Actinomycetes
C. Progenote
D. Archaebacteria.

Answer

To answer the question "The most primitive of monerans are," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of Monerans**:
- Monerans are non-nucleated unicellular organisms. This means they do not have a true nucleus and are made up of only one cell.

2. **Characteristics of Monerans**:
- They lack membrane-bound organelles such as mitochondria and Golgi complex.
- They have a nucleoid, which contains genetic material but lacks a nuclear membrane.

3. **Examples of Monerans**:
- Common examples of monerans include bacteria, archaebacteria, mycoplasma, and blue-green algae.

4. **Identify the Most Primitive Monerans**:
- Among the examples provided, archaebacteria (often referred to as "RK bacteria") are considered the most primitive forms of monerans.

5. **Evaluate the Options**:
- The options given are:
1. Rickettsiae
2. Actinomycetes
3. Progenote
4. Archaebacteria
- Based on our understanding, archaebacteria is the correct answer as it represents the most primitive group of monerans.

6. **Conclusion**:
- Therefore, the most primitive of monerans are **Archaebacteria**.

### Final Answer:
The correct option is **4. Archaebacteria**.

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