Final answer:
The plasma membrane is fluid but unorganized, composed of a phospholipid bilayer. Proteins in the membrane contribute to its fluidity and functionality.
Step-by-step explanation:
The plasma membrane, also known as the cell membrane, is composed of a phospholipid bilayer that exhibits fluidity. It is best characterized as fluid but unorganized. The proteins embedded in the membrane contribute to its fluidity and allow for various functions such as transporting molecules and transmitting signals.
Learn more about Structure of the plasma membrane