AP BIOLOGY

Detailed explanation-1: -The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space).

Detailed explanation-2: -The plasma membrane, also called the cell membrane, is the membrane found in all cells that separates the interior of the cell from the outside environment.

Detailed explanation-3: -The cell membrane is also called the plasma membrane or the plasmalemma.

Detailed explanation-4: -Why it is called a plasma membrane? The cell contains a protoplasm (or simply plasm), which is the semi-fluid living matter. This living matter or plasm is contained inside a biological membrane referred to as the plasma membrane.