Which of the following best describes the relationship between osmosis and diffusion?

• A. Osmosis is a specific type of diffusion that involves the movement of water molecules across a semipermeable membrane.
• B. Diffusion requires a semipermeable membrane, while osmosis does not.
• C. Diffusion only occurs in solids, while osmosis only occurs in liquids.
• D. Osmosis and diffusion are completely unrelated processes.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of diffusion. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration, driven by the concentration gradient, and it can occur in gases, liquids, or solids without the need for a membrane.
2. Step 2: Understand the definition of osmosis. Osmosis is a special type of diffusion that specifically involves the movement of water molecules across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.
3. Step 3: Compare the two processes. While diffusion can involve any type of molecule moving down its concentration gradient and does not require a membrane, osmosis is restricted to water molecules and requires a semipermeable membrane that allows only water to pass through.
4. Step 4: Analyze the given answer choices based on these definitions. Identify which statement correctly reflects that osmosis is a specific case of diffusion involving water and a semipermeable membrane.
5. Step 5: Conclude that the best description is that osmosis is a specific type of diffusion involving water molecules moving across a semipermeable membrane, distinguishing it from general diffusion.