Question

Is the cell membrane semi permeable or selectively permeable? Name the three ways selective permeability takes place. [2 MARKS]

Answer 1

Explanation : 1 Mark
Naming : 1 Mark

The cell is selectively permeable. Selective permeability means that the cell membrane has some control over what can cross it, so that only certain molecules either enter or leave the cell.

Molecules can cross the plasma membrane in three main ways. They are

• Simple diffusion
• Facilitated diffusion
• Active transport