Answer:Self-assembly into a simple membrane
Step-by-step explanation:
The cell membrane is the biological membrane that separates the interior of the cell to the exterior of the cell.
The cell membrane is made of lipid by-layer. The first cell membrane was made of lipids. It is so because it has the ability to assemble and form a membrane like structure.
It helps in entry and exit of the substances from inside of the cell to outside and vice versa.