Question

active transport ________. a moves materials against their concentration gradients b requires energy c occurs in cells with many mitochondria d all apply.

Explanation:

• Option A: Active transport moves substances from low to high concentration, i.e., against concentration gradients.
• Option B: Since it moves against gradients, it needs energy (e.g., ATP) to do so.
• Option C: Mitochondria produce energy (ATP). Cells with active transport (like kidney cells) have many mitochondria to supply energy.
• So all options (A, B, C) are correct about active transport.

Answer:

D. All apply.