Question

multiple choice question the net movement of a substance from high concentration to low is called ______.
active transport
transduction
bulk transport
diffusion

Explanation:

• Active transport moves substances from low to high concentration (requires energy), so it's incorrect.
• Transduction is about signal conversion (e.g., in cells or genetics), not substance movement by concentration gradient.
• Bulk transport involves moving large quantities/particles (e.g., endocytosis/exocytosis), not based on concentration gradient of small substances.
• Diffusion is defined as the net movement of a substance from an area of high concentration to low concentration (down the concentration gradient), matching the description.

Answer:

D. diffusion