Answer:
Homeostasis
Step-by-step explanation:
Cell membrane (plasma membrane) is known to be a semi-permeable membrane that regulates the movement of substances in and out of the cell. Similarly, it is a phospholipid bilayer that separates the outer (external) environment from the inner cellular environment. Thus, plasma membrane maintains homeostasis by regulating the movement of materials or cell contents that can pass in or out of the cell on order to main balance equilibrium.