What is the key difference between diffusion and osmosis?

What is the key difference between diffusion and osmosis?

• A. Diffusion involves movement of ions only; osmosis involves water
• B. Osmosis requires energy, diffusion does not
• C. Diffusion is random movement of any solutes; osmosis is specifically water diffusion
• D. Both involve water movement; osmosis involves solutes

Answer: (C)

The key distinction is that diffusion is the general movement of particles from an area of higher concentration to an area of lower concentration and can involve any type of molecule or ion in a solution or gas. Osmosis, on the other hand, is a specific type of diffusion that describes the movement of water across a selectively permeable membrane, from where there is more water (lower solute concentration) to where there is less water (higher solute concentration). Both processes occur passively without using cellular energy. The other statements misstate what diffuses (it’s not only ions) or what osmosis moves (water, not solutes), and they incorrectly claim energy is required.

The key distinction is that diffusion is the general movement of particles from an area of higher concentration to an area of lower concentration and can involve any type of molecule or ion in a solution or gas. Osmosis, on the other hand, is a specific type of diffusion that describes the movement of water across a selectively permeable membrane, from where there is more water (lower solute concentration) to where there is less water (higher solute concentration). Both processes occur passively without using cellular energy. The other statements misstate what diffuses (it’s not only ions) or what osmosis moves (water, not solutes), and they incorrectly claim energy is required.