The cell membrane has a bilayer that contains _________ heads and _________ tails to create a semi permeable membrane.

The bilayer is created by multiple phospholipids that come together to isolate the cell components and the extracellular environment. Phospholipids contain a hydrophobic tail and a hydrophilic head. The hydrophobic tail is made up of two hydrocarbon chains that are non-polar (hydrophobic). The hydrophilic heads are polar and form hydrogen bonds with water.