Question

which of the following statements correctly describes the difference between osmosis and simple diffusion?

• osmosis occurs directly through the cell membrane and simple diffusion occurs through a transport protein.
• osmosis is an example of active transport and simple diffusion is an example of passive transport.
• osmosis moves water with its concentration gradient and simple diffusion moves water against its concentration gradient.
• osmosis refers to the movement of water and simple diffusion refers to the movement of solutes.

Explanation:

To solve this, we analyze each option based on the concepts of osmosis and simple diffusion (both passive transport, moving down concentration gradients; osmosis is water movement, simple diffusion is solute movement):

Option 1:

Osmosis moves water, simple diffusion moves solutes (down their concentration gradients). This matches their definitions.

Option 2:

Osmosis (water) and simple diffusion (solutes) move down concentration gradients (passive), not against. Eliminate.

Option 3:

Osmosis and simple diffusion are passive (no energy, down gradient), while active transport requires energy (up gradient). So osmosis/simple diffusion are not active transport. Eliminate.

Option 4:

Osmosis and simple diffusion are passive (no transport proteins needed for simple diffusion; osmosis uses aquaporins but is still passive). Active transport uses proteins. Eliminate.

• Analyze each option against osmosis (water, passive, down gradient) and simple diffusion (solute, passive, down gradient) definitions.
• Option 1 correctly states osmosis moves water and simple diffusion moves solutes (both down gradients). Other options have errors (moving against gradient, classifying as active, or requiring transport proteins).

Answer:

The correct option (assuming the first option’s text is "Osmosis refers to the movement of water and Simple Diffusion refers to the movement of solutes") is the one with this description (e.g., if it’s option A, then: A. Osmosis refers to the movement of water and Simple Diffusion refers to the movement of solutes).