The plasma membrane forms a what between the inside and outside of the cell?

Plasma membrane forms a stable barrier.

Explanation:Cell membrane is a thin flexible membrane, it is present in every living cell.It is also known as plasma membrane or cytoplasmic membrane. This membrane is selectively permeable to organic molecules and ions. It is made up of proteins and lipidsThis membrane forms a stable barrier between two aqueous compartments i.e. to separate the inside of cells from the outside. Cell membrane separates the cytoplasm of the cell from the surroundings.

Result: Plasma membrane act as a barrier to protect the cell content from the surroundings.

Probably a behavioral adaptation