Biology

The correct answer is: B.Phospholipid bilayer

The cell membrane is primarily made up of a phospholipid bilayer, which forms the basic structural foundation of the membrane. The bilayer consists of two layers of phospholipids, with hydrophobic (water-repellent) fatty acid tails facing inward and hydrophilic (water-attracting) phosphate heads facing outward.

Here’s why the other options are incorrect:

A.Rigid cellulose outer layer: This is characteristic of plant cell walls, not the cell membrane. The cell membrane is flexible, not rigid like cellulose.