Question

why do pumps require energy?
○ pumps move substances from areas of high concentration to areas of low concentration.
○ pumps move substances from areas of low concentration to areas of high concentration.
○ pumps always move substances out of the cell.
○ pumps always move substances into the cell.

Explanation:

To determine why pumps require energy, we analyze each option:

• The first option describes passive transport (diffusion), which doesn't need energy.
• The second option: Pumps (like in active transport) move substances against the concentration gradient (from low to high concentration). This process requires energy (e.g., ATP) to overcome the natural tendency of substances to move down the concentration gradient.
• The third and fourth options are incorrect because pumps can move substances into or out of the cell, not always one direction.

Answer:

B. Pumps move substances from areas of low concentration to areas of high concentration.