which of the following statements are true regarding active transport and facilitated diffusion (choose two answers) a) Active transport utilizes channel proteins and facilitated diffusion utilizes carrier proteins b) Both processes require the use of membrane proteins c) Both processes require the input of energy (ATP) d) Active transport moves substances against the concentration gradient and facilitated diffusion moves substances along the concentration gradient

B and D

Explanation: We can break down why the correct answers are choices B and D by understanding why A and C are incorrect.

Option A states that active transport utilizes channel proteins, and facilitated diffusion utilizes carrier proteins. This is incorrect. Active transport involves carrier proteins, and facilitated diffusion involves channel proteins. Carrier proteins are different from channel proteins in that, while channel proteins can only facilitate the passive diffusion of ions into or out of the cell along their concentration gradient, carrier proteins can also use ATP to move ions in or out of the cell against their concentration gradient.

This brings us to why option C is also incorrect. Option C states that both processes require the input of energy in the form of ATP. While active transport requires the use of ATP to transport ions with or against their concentration gradient, facilitated diffusion does not. This is easily remembered when we consider that active transport is called *active* transport because the cell is *actively* using energy to transport ions.

Hope this helped.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.