Phospholipids make up most of the lipid part of the cell membrane. since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense?
a. a single layer of phospholipids with the polar heads facing outside the cell
b. two back-to-back phospholipid layers with the non-polar tails facing out on both sides
c. a single layer of phospholipids with the polar heads facing inside the cell
d. two back-to-back phospholipid layers with the polar heads facing out on both sides

The correct option is D. (Two back-to-back phospholipid layers with the polar heads facing out on both sides)

Explanation:

The plasma membrane creates a barrier between the interior part of the cell and the cytoplasm. It is consisting of proteins and phospholipids and bi-layered in nature. Phospholipids are known as the main component of the plasma membrane.

Phospholipids are composed of alcohol and fatty acids and they are arranged in a specific manner. Each phospholipid molecule contains a water-hating tail that is hydrophobic in nature and a water-loving head which is hydrophilic in nature and the polar heads face the outside.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.