What is the ability of the plasma membrane to control the passage of certain materials into and out of the cell called?

The ability of the plasma membrane to control the passage of certain materials into and out of the cell is referred to as selective permeability. This property allows the cell to maintain homeostasis by regulating which substances can enter or leave, ensuring that essential nutrients, ions, and water are acquired while harmful substances are kept out. Selective permeability is achieved through various mechanisms, including the lipid bilayer's hydrophobic nature and the presence of specific transport proteins that facilitate or block the movement of certain molecules.

Other processes, like active transport and facilitated diffusion, are mechanisms that operate within the framework of selective permeability. Active transport involves the movement of substances against their concentration gradient, which requires energy. Facilitated diffusion refers to the passive movement of molecules across the membrane via transport proteins, but it still falls under the overarching principle of selective permeability. Osmotic pressure, on the other hand, relates to the movement of water across a membrane and is influenced by the concentration of solutes, rather than describing the membrane's ability to selectively allow material in and out.