Biology

The primary function of the phospholipid bilayer in the cell membrane is: B. Acting as a protective barrier

The phospholipid bilayer forms the structural foundation of the cell membrane. It creates a semi-permeable barrier that separates the cell's internal environment from the outside, protecting the cell and controlling the passage of substances (like ions, nutrients, and waste) into and out of the cell. The hydrophobic (water-repelling) interior of the bilayer prevents the free passage of water-soluble substances, which is crucial for maintaining homeostasis within the cell.

Explanation of other options:

A. Facilitating protein synthesis: Protein synthesis occurs in the ribosomes (not directly...