Question

question ① which of the following is correct regarding the movement of substances against their concentration gradient? select all that apply active transport facilitated diffusion requires energy does not depend on a gradient

Explanation:

1. Active transport: Moves substances against concentration gradient, so this applies.
2. Facilitated diffusion: Moves substances down concentration gradient (with help of proteins), so this does not apply.
3. Requires energy: Moving against concentration gradient (active transport) needs energy (e.g., ATP), so this applies.
4. Does not depend on a gradient: Active transport is against the gradient, meaning it's not dependent on the natural flow of the gradient (since it's going opposite), so this applies as the movement is against, so it's not relying on the gradient's direction for flow (though the gradient exists, the movement is against it, so in terms of the driving force for the movement, it's not dependent on the gradient to go that way—energy is the driver).

Answer:

A. Active transport, C. Requires energy, D. Does not depend on a gradient