What does the cell membrane do in osmosis and defussion

The primary purpose of the cell membrane is to preserve the cell from its surroundings

The primary purpose of the cell membrane is to preserve the cell from its surroundings.The cell membrane is also named selectively permeable membrane for the single reason being it is particular in nature. Furthermore, in diffusion and osmosis, only specific molecules transfer through the cell membrane. Diffusion helps the entrance of important molecules like water, carbon, and oxygen.