Answer: Q1. The primary function of the plasma membrane is to protect the cell from its surroundings. Composed of a phospholipid bilayer with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules and regulates the movement of substances in and out of cells.
Q2. The phospholipids in the cell membrane are arranged in two layers, called a phospholipid bilayer. Each phospholipid molecule has a head and two tails.
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