Choose the incorrect statement regarding cell membrane.

Options

A. Generally smaller molecules pass easily and readily than large molecules.
B. Water soluble substance pass through it less readily than lipid soluble substances.
C. In addition to phosholipid membrane it also contains cholesterol.
D. None of these

Answer

To determine the incorrect statement regarding the cell membrane, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Understanding the Cell Membrane Structure**:
- The cell membrane is primarily composed of a phospholipid bilayer, which consists of hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails. This structure allows the membrane to be selectively permeable.

2. **Analyzing Option A**:
- **Statement**: "Generally smaller molecules pass easily readily than larger molecules."
- **Evaluation**: This statement is true. Smaller molecules can diffuse through the membrane more easily than larger molecules due to size.

3. **Analyzing Option B**:
- **Statement**: "Water molecule substances pass through it less readily than the lipid soluble substances."
- **Evaluation**: This statement is incorrect. Water molecules, being small, can pass through the cell membrane relatively easily, especially through specialized channels (aquaporins). Lipid-soluble substances pass through more readily than water-soluble substances due to the hydrophobic nature of the membrane.

4. **Analyzing Option C**:
- **Statement**: "In addition to phospholipid membrane, it also contains cholesterol."
- **Evaluation**: This statement is true. Cholesterol is indeed present in the cell membrane and helps maintain its fluidity and stability.

5. **Analyzing Option D**:
- **Statement**: "None of these."
- **Evaluation**: This option suggests that all previous statements are true. However, since we identified that Option B is incorrect, this option cannot be correct.

### Conclusion:
The incorrect statement regarding the cell membrane is **Option B**: "Water molecule substances pass through it less readily than the lipid soluble substances."