Question

Which of the following is a function of membranes?

1) compartmentalization
2) selectively permeable barrier
3) mediates intercellular interactions
4) helps cells respond to external stimuli
5) All of these are correct.

Answer 1

Cell membranes perform multiple vital functions including compartmentalization, acting as selectively permeable barriers, mediating intercellular interactions, and enabling cells to respond to external stimuli. All options listed are correct functions of cell membranes.

Step-by-step explanation:

The question pertains to the functions of cell membranes or plasma membranes. These structures serve several critical roles:

1. Compartmentalization: Membranes organize the internal structures of cells into compartments, separating the cellular machinery and various metabolic pathways.
2. Selectively permeable barrier: The membrane's selective permeability allows certain substances to enter and leave the cell while keeping others out, contributing to the cell's internal balance.
3. Mediates intercellular interactions: Membranes carry markers and receptors that facilitate communication and interaction between cells.
4. Helps cells respond to external stimuli: Receptors on cell membranes allow cells to detect and respond to changes in their environment.

All of these options, therefore, are correct. The cell membrane's permeability is a key feature that maintains growth and dynamic homeostasis by regulating the movement of molecules across it.