Question

Why is cell membrane called a selectively permeable membrane?

• A. It is permeable only during certain stage of the cell division.
• B. It allows only selective molecules to pass through it.
• C. It allows only water to pass.
• D. It is made up of lipids.

Answer 1

The correct option is B It allows only selective molecules to pass through it.

Plasma membrane is an external covering of the cell. It separates the contents of the cell from the external surroundings. Since, it allows the entry and exit of only certain substances (e.g., molecules, ions, etc.) it is known as a selectively permeable membrane.