Florida State Paramedic Practice Exam

What term describes the movement of water across a membrane?

1. Diffusion

2. Osmosis

3. Active transport

4. Endocytosis

The correct answer is: Osmosis

The correct answer is osmosis. Osmosis specifically refers to the movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. This process is crucial for maintaining cellular homeostasis, as it allows cells to regulate their internal environment by controlling water balance. The nature of osmosis helps in understanding how cells interact with their environment and manage fluid balance. It differs from diffusion, which pertains to the movement of solutes rather than water. Active transport involves the movement of substances against their concentration gradient, requiring energy, whereas endocytosis is a mechanism for engulfing substances into the cell but does not pertain specifically to the movement of water molecules. Recognizing osmosis is essential for comprehending fluid dynamics in biological systems, particularly in healthcare contexts like fluid replacement and hydration strategies.