Which statement best describes the function of the cell membrane?

Which statement best describes the function of the cell membrane?

• A. It stores genetic material
• B. It produces energy for the cell
• C. It transports proteins to the nucleus
• D. It controls what enters and leaves the cell

Answer: (D)

The cell membrane acts as a gatekeeper for the cell’s interior. It’s a boundary made of a phospholipid bilayer with proteins that form channels and pumps, which lets some substances through while blocking others. This selective permeability keeps the inside of the cell at the right conditions for life, allowing nutrients to enter, gases to pass, and wastes to exit. Because of this gatekeeping role, the membrane helps maintain homeostasis, the stable environment the cell needs to function. Storing genetic material happens in the nucleus, not the membrane. Energy is produced mainly by mitochondria. Transporting proteins to the nucleus involves processes inside the cell, not moving them through the cell membrane. So the best description of the membrane’s function is that it controls what enters and leaves the cell.

The cell membrane acts as a gatekeeper for the cell’s interior. It’s a boundary made of a phospholipid bilayer with proteins that form channels and pumps, which lets some substances through while blocking others. This selective permeability keeps the inside of the cell at the right conditions for life, allowing nutrients to enter, gases to pass, and wastes to exit. Because of this gatekeeping role, the membrane helps maintain homeostasis, the stable environment the cell needs to function.

Storing genetic material happens in the nucleus, not the membrane. Energy is produced mainly by mitochondria. Transporting proteins to the nucleus involves processes inside the cell, not moving them through the cell membrane. So the best description of the membrane’s function is that it controls what enters and leaves the cell.