Spiral Review - Diffusion

What is the definition of diffusion?

• The movement of a substance from low to high concentration.

• The net movement of a substance traveling down its concentration gradient.

• The movement of a substance that requires energy.

• The movement of a substance against its concentration gradient.

Which statement accurately describes diffusion as a type of transport?

• It requires an input of energy (ATP).

• It moves substances against their concentration gradient.

• It is a passive transport, meaning no added energy is required.

• It only occurs in water.

What distinguishes facilitated diffusion from simple diffusion?

• Facilitated diffusion requires energy, while simple diffusion does not.

• Facilitated diffusion moves substances against their concentration gradient.

• Facilitated diffusion requires a protein channel for molecules to cross the membrane.

• Facilitated diffusion only occurs in gases.

How does temperature generally affect the rate of diffusion?

• Lower temperatures increase the diffusion rate.

• Higher temperatures decrease the diffusion rate.

• Higher temperatures increase the diffusion rate due to more molecular movement.

• Temperature has no effect on the diffusion rate.