Which statement best describes passive transport?

Which statement best describes passive transport?

• A. Requires energy
• B. Does not require energy
• C. Involves vesicles
• D. Involves channels

Answer: (B)

Passive transport moves substances across the cell membrane without the cell using energy. Molecules spread down their concentration gradient because of their own random motion, so they go from areas of higher concentration to lower concentration. Some forms, like facilitated diffusion, use channel or carrier proteins to help certain molecules cross, but they still don’t require cellular energy. This energy-free movement distinguishes passive transport from active transport, which needs ATP, and from vesicle-based transport, which also consumes energy. So the statement that passive transport does not require energy best captures how this process works.

Passive transport moves substances across the cell membrane without the cell using energy. Molecules spread down their concentration gradient because of their own random motion, so they go from areas of higher concentration to lower concentration. Some forms, like facilitated diffusion, use channel or carrier proteins to help certain molecules cross, but they still don’t require cellular energy. This energy-free movement distinguishes passive transport from active transport, which needs ATP, and from vesicle-based transport, which also consumes energy. So the statement that passive transport does not require energy best captures how this process works.