Question

question 18
diffusion occurs because of ____a__, whereas active transport occurs because of __b____.
in the statement above the best phrase to fill space b is:
energy
tonicity
concentration gradients
turgor pressure

Explanation:

Diffusion is a passive process that occurs due to concentration gradients, moving substances from high - to low - concentration areas. Active transport, on the other hand, requires energy (such as ATP) to move substances against their concentration gradient.

Answer:

energy