Kaplan Nursing Entrance Practice Exam

What is the most inclusive process that includes diffusion, osmosis, and facilitated transport?

1. Active Transport

2. Passive Transport

3. Diffusion

4. Filtration

The correct answer is: Passive Transport

The most inclusive process that includes diffusion, osmosis, and facilitated transport is passive transport. Passive transport describes the movement of molecules across a cell membrane without the need for energy expenditure from the cell. This process relies on concentration gradients, meaning substances move from areas of higher concentration to areas of lower concentration. Diffusion is a fundamental mechanism of passive transport where molecules spread from an area of higher concentration to an area of lower concentration. Osmosis is a specific type of diffusion that involves the movement of water across a semipermeable membrane, also following concentration gradients. Facilitated transport, also known as facilitated diffusion, involves carrier proteins or channels to help specific molecules cross the membrane more efficiently, but it still does not require energy. All three processes—diffusion, osmosis, and facilitated transport—fall under the umbrella of passive transport because they move substances along their concentration gradients, contributing to the dynamic equilibrium of the cell environment without expending energy. Active transport, in contrast, involves the movement of substances against their concentration gradients and requires energy input, making it distinct from passive transport.