Question

what describes the movement of substances down their concentration gradients? multiple choice saturation bulk transport active transport diffusion

Explanation:

• Saturation refers to a state where a solution or system has dissolved or absorbed the maximum amount of a substance, not related to movement down concentration gradients.
• Bulk transport involves the movement of large molecules or particles (like endocytosis and exocytosis) and is not specifically about moving down concentration gradients.
• Active transport moves substances against their concentration gradients (from low to high concentration) using energy.
• Diffusion is the process by which substances move from an area of higher concentration to an area of lower concentration (down their concentration gradient) without the need for energy input.

Answer:

D. Diffusion