How is the plasma membrane of a cell organized?
question 15 options:

one layer of phospholipids, through which proteins freely move

one layer of phospholipids, which are laid out end-to-end, with a hydrophobic tail touching a hydrophilic head

two layers of phospholipids, each of which has its hydrophilic side turned inward

two layers of phospholipids, with their polar hydrophilic heads facing away from each other

The correct answer is two layers of phospholipid with their polar hydrophilic heads facing away from each other.

Explanation:

The plasma membrane is composed of phospholipid bilayer in which the protein molecules are embedded .Each phospholipid of the phospholipid bilayer contain a glycerol head group that are arranged in the extracellular region away from each other.

     whereas the fatty acid chain of the the phospholipid molecules of both the layer faces each other in the hydrophobic region of the plasma membrane.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%