Question

1. which of the following is an accurate comparison of passive transport and active transport?

a. passive transport occurs through protein pumps or endocytosis, whereas active transport occurs through osmosis or diffusion.
b. passive transport uses atp to move molecules across a cell membrane, whereas active transport uses a hydrostatic pressure gradient to push molecules from a higher - pressure area to a lower - pressure area.
c. in passive transport, cells use energy to move molecules through their passive membranes, whereas in active transport, cells let their active membranes pull molecules through.
d. in passive transport, certain molecules move through the cells selectively permeable membrane without the cell using any energy, whereas in active transport, cells use specialized channels or carriers to move molecules across the membrane.

Explanation:

• Option a: Passive transport includes osmosis and diffusion, while active transport includes protein pumps and endocytosis. This option swaps them, so it's incorrect.
• Option b: Passive transport does not use ATP (it's energy - free), and active transport uses ATP, not a hydrostatic pressure gradient for the typical movement against concentration gradients. So this option is incorrect.
• Option c: Passive transport does not use energy, and there are no “passive” or “active” membranes. The cell membrane is selectively permeable. This option has incorrect descriptions, so it's wrong.
• Option d: Passive transport (like diffusion, osmosis, facilitated diffusion) allows molecules to move across the selectively permeable membrane without the cell expending energy. Active transport uses specialized channels (like protein pumps) or carriers and requires energy (usually ATP) to move molecules against their concentration gradient. This option correctly describes the key differences.

Answer:

d. In passive transport, certain molecules move through the cell's selectively permeable membrane without the cell using any energy, whereas in active transport, cells use specialized channels or carriers to move molecules across the membrane.