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. simple diffusion is a type of passive transport, while facilitated diffusion is a type of active transport. large, nonpolar molecules are able to cross the cell membrane by osmosis. cellular energy is not required to move molecules from areas of higher concentration to areas of lower concentration. as molecules move randomly, they collide with each other and spread out down their concentration gradients.

Explanation:

• For the first statement: Both simple diffusion and facilitated diffusion are types of passive transport as they do not use cellular energy. So the first statement is false.
• For the second statement: Osmosis is the movement of water molecules (not large non - polar molecules) across a semi - permeable membrane. Large non - polar molecules can cross the membrane by simple diffusion. So the second statement is false.
• For the third statement: Passive transport (which moves molecules from higher to lower concentration) does not require cellular energy. So this statement is true.
• For the fourth statement: According to the kinetic theory of matter, molecules in motion collide and spread out (diffuse) down their concentration gradients. So this statement is true.

Answer:

• Cellular energy is not required to move molecules from areas of higher concentration to areas of lower concentration.
• As molecules move randomly, they collide with each other and spread out down their concentration gradients.