Question

question 13
according to the fluid mosaic model of cell membrane structure, proteins of the membranes are mostly:
spread in a continuous layer over the inner and outer surfaces of the membrane
attached to the cholesterol in animal cell membranes.
embedded in a phospholipid bilayer
no answer text provided.

Explanation:

The fluid mosaic model describes the cell membrane as a dynamic structure. Phospholipids form a bilayer. Proteins are embedded within this bilayer. They can be integral (span the bilayer) or peripheral (associated with one side). This arrangement allows for functions like transport, signaling, and structural support. The other options are incorrect: proteins are not in a continuous layer (disproven by freeze - fracture techniques), and while cholesterol is in animal membranes, proteins are not mainly attached to it.

Answer:

embedded in a phospholipid bilayer