Cell membrane is

Options

A. Permeable
B. Impermeable
C. Semi permeable
D. Differentially permeable

Answer

**Step-by-Step Solution:**

1. **Understanding the Cell Membrane**: The cell membrane, also known as the plasma membrane, surrounds the cell and encloses its contents, including the cytoplasm.

2. **Defining Permeability**: Permeability refers to the ability of a membrane to allow substances (solutes and solvents) to pass through it.

3. **Analyzing the Options**:
- **A. Permeable**: This means the membrane allows both solute and solvent to pass through freely.
- **B. Impermeable**: This means the membrane does not allow either solute or solvent to pass through.
- **C. Semi-permeable**: This means the membrane allows only the solvent to pass through, not the solute.
- **D. Differentially Permeable**: This means the membrane selectively allows certain molecules to pass through while restricting others.

4. **Identifying the Correct Option**: The cell membrane is best described as differentially permeable because it selectively allows certain substances to enter or exit the cell while blocking others.

5. **Conclusion**: Therefore, the correct answer to the question "Cell membrane is" is option D: differentially permeable.

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