Cell principle is not applicable to

Options

A. Bacteria
B. Viruses
C. Algae
D. Fungi

Answer

To solve the question "Cell principle is not applicable to", we will analyze the options provided and apply our understanding of the cell theory.

### Step-by-Step Solution:

1. **Understand the Cell Principle**:
- The cell principle, or cell theory, states that all living organisms are composed of cells, and the cell is the basic unit of life. This principle applies to all living organisms.

2. **Analyze the Options**:
- **Option A: Bacteria**: Bacteria are single-celled organisms and are composed of cells. They are living organisms, so the cell principle applies to them.
- **Option B: Viruses**: Viruses are unique because they are not considered living organisms outside of a host. They do not have a cellular structure and cannot replicate on their own. Therefore, the cell principle does not apply to viruses.
- **Option C: Algae**: Algae are also composed of cells and are classified as living organisms. Thus, the cell principle applies to them.
- **Option D: Fungi**: Fungi are multicellular organisms (with some unicellular forms like yeast) and are made up of cells. Therefore, the cell principle applies to fungi as well.

3. **Conclusion**:
- Since the cell principle applies to all living organisms except for those that are not considered living, the correct answer is **Option B: Viruses**.

### Final Answer:
**Option B: Viruses**