Question

passive transport occurs when molecules cross the cell membrane without using cellular energy. molecules cross the cell membrane by three main types of passive transport: simple diffusion, facilitated diffusion, and osmosis. select the true statements. energy from the cell is required to move molecules from areas of higher concentration to areas of lower concentration. simple diffusion moves molecules from areas of higher to lower concentration, while facilitated diffusion moves molecules from areas of lower to higher concentration. as molecules move randomly, they collide with each other and spread out down their concentration gradients. all molecules are able to cross the cell membrane by osmosis.

Explanation:

1. In passive transport, moving molecules from higher - to lower - concentration areas does not require cellular energy. So the first statement is false.
2. Both simple and facilitated diffusion move molecules from higher to lower concentration areas. The second statement is false.
3. Molecules do move randomly and spread down their concentration gradients due to collisions in diffusion, but this is not a complete and accurate description of all passive - transport processes. However, the statement itself is a correct description of the basic principle of diffusion.
4. Only water molecules cross the cell membrane by osmosis, not all molecules. So the fourth statement is false.

Answer:

None of the above statements are true.