Which is not the function of cell wall ?
I. Provides shape to the cell
II. Protects the cell from mechanical damage and infection
III. Helps in cell to cell interaction
IV. Provides barrier to undesirable macromolecules
V. Imbibition of water

Options

A. Only III
B. Only IV
C. Only II , III and IV
D. None of these

Answer

To determine which option is not a function of the cell wall, we will analyze each statement provided in the question.

### Step-by-Step Solution:

1. **Understanding the Cell Wall**: The cell wall is a rigid outer layer found in plant cells, fungi, and some prokaryotes. It provides structural support and protection.

2. **Analyzing Each Statement**:
- **I. Provides shape to the cell**: This is a function of the cell wall. It maintains the shape of the plant cell.
- **II. Protects the cell from mechanical damage and infection**: This is also a function of the cell wall. It acts as a protective barrier against physical damage and pathogens.
- **III. Helps in cell to cell interaction**: This is true as well. The cell wall contains structures like plasmodesmata that facilitate communication and transport between adjacent cells.
- **IV. Provides barrier to undesirable macromolecules**: This statement is correct. The cell wall can act as a barrier to prevent harmful substances from entering the cell.
- **V. Imbibition of water**: This statement is somewhat misleading. While the cell wall can absorb water, the primary function of imbibition is typically associated with the plasma membrane and cytoplasm rather than the cell wall itself.

3. **Identifying the Incorrect Function**: Among the options, statement V (Imbibition of water) is not primarily a function of the cell wall. The cell wall does not play a significant role in the process of imbibition compared to other cellular structures.

4. **Conclusion**: Therefore, the option that is not a function of the cell wall is **V. Imbibition of water**.

### Final Answer:
**V. Imbibition of water**