Question

question 18
why does diffusion not require energy?
a particles are moving in the directions they naturally flow
b particles are moving using atp molecules
c the cell is pumping the particles through the membrane
d diffusion involves the membrane opening up at a specific location

Explanation:

Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. This is a passive process as it occurs along the concentration gradient (the natural flow of particles). ATP is used in active transport (not diffusion). "Pumping" particles (active transport) and membrane opening at a specific location (like in some channel - mediated processes which may or may not be active) are not characteristics of simple diffusion.

Answer:

A. Particles are moving in the directions they naturally flow