Which part of the cell membrane does not mix with water?

O

A. Nucleus

O

O

O

B. Fatty acids

C. Phosphate groups

D. Cytosol

The correct answer is C

It's c the phosphate groups

So the phospholipids are arranged in a double layer (a bilayer) to keep the cell separate from its environment. Lipids do not mix with water (recall that oil is a lipid), so the phospholipid bilayer of the cell membrane acts as a barrier, keeping water out of the cell, and keeping the cytoplasm inside the cell.