Question

bio - 201 topic 2: cell physiology & tissues
practice it
what is the cell membrane?
a layer of protein that surrounds the nucleus of a cell.
a region of a cell that synthesizes lipids and other molecules.
a barrier that separates the interior content of the cell from the outside environment.
a structure that stores genetic material in a cell.
a protective layer that covers the surface of a cell.

Explanation:

The cell membrane is a biological structure that acts as a selective - barrier, separating the cell's interior from the external environment. It is composed of a phospholipid bilayer with embedded proteins and has functions like regulating the movement of substances in and out of the cell. The first option describes the nuclear envelope, the second describes the endoplasmic reticulum, the fourth describes the nucleus, and the fifth is an inaccurate description compared to the barrier - function definition.

Answer:

A barrier that separates the interior content of the cell from the outside environment.