Which of the following statement is incorrect regarding cell coat ?

Options

A. It is present in animals, bacteria and protistans.
B. In some cases cell coat is thickened by deposition of calcium, silicon and other salts.
C. It helps in recognition between microbe and body cell by WBCs and involved in histocompatibility.
D. It helps in cell aggregation and tissue formation.

Answer

To determine which statement is incorrect regarding the cell coat, also known as glycocalyx, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Cell Coat (Glycocalyx)**:
- The cell coat, or glycocalyx, is a layer that covers the outer surface of animal cells. It is primarily composed of carbohydrates, specifically oligosaccharides that are attached to proteins (glycoproteins) and lipids (glycolipids).

2. **Analyzing the Options**:
- **Option 1**: "It is present in animals, bacteria, and protistians."
- This statement is correct. Glycocalyx is indeed found in animals, bacteria, and protists.

- **Option 2**: "In some cases, the cell coat is thickened by the deposition of calcium, silicon, and other salts."
- This statement is incorrect. The glycocalyx is not typically thickened by calcium, silicon, or other salts; it is primarily composed of carbohydrates.

- **Option 3**: "It helps in the recognition between microbe and the body cell via the white blood cell and involves in the histocompatibility."
- This statement is correct. The glycocalyx plays a role in cell recognition and is involved in immune responses, including histocompatibility.

- **Option 4**: "It helps in cell aggregation and tissue formation."
- This statement is also correct. The glycocalyx aids in cell adhesion and the formation of tissues.

3. **Conclusion**:
- The incorrect statement regarding the cell coat is **Option 2**.

### Final Answer:
The incorrect statement regarding the cell coat is: **"In some cases, the cell coat is thickened by the deposition of calcium, silicon, and other salts."**

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