Final answer:
The fluid nature of the plasma membrane, as described in the fluid mosaic model, is advantageous because it allows for the exchange of materials, providing flexibility needed for transport, signaling, and adapting to changes.
Step-by-step explanation:
The fluid mosaic model describes the structure of the plasma membrane as composed of a diversity of lipids and proteins that allow for a fluid nature. This fluidity is crucial for a cell's functionality. Among the options presented, the correct answer is (b) Allows for the exchange of materials. This fluid nature is advantageous because it permits integral proteins and lipids to move and reorganize, which is essential for facilitating the transport of substances across the membrane, signaling processes, and the maintenance of the cell's structural integrity. The components of the membrane are not rigidly fixed in place but can move laterally, allowing the cells to adapt to changes and stresses, interact with external molecules, and perform various biological functions effectively. The molecular components, including phospholipids, cholesterol, and proteins, contribute to the fluidity, making the plasma membrane flexible but not prone to bursting under normal conditions.