Question

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simple and facilitated diffusion differ because
multiple choice
simple diffusion requires the presence of a transport protein within the plasma membrane, while facilitated diffusion does not
ions being transported by simple diffusion move along their electrochemical gradients, while ions being transported by facilitated diffusion move against their electrochemical gradients
ions being transported by simple diffusion move against their electrochemical gradients, while ions being transported by facilitated diffusion move along their electrochemical gradients
facilitated diffusion requires the presence of a transport protein within the plasma membrane, while simple diffusion does not

Explanation:

Simple diffusion is the passive movement of substances from an area of high concentration to low concentration without the help of transport proteins. Facilitated diffusion is also a passive process but requires transport proteins (channels or carriers) in the plasma - membrane to move substances (usually larger or polar molecules, or ions) down their concentration or electrochemical gradients.

Answer:

D. facilitated diffusion requires the presence of a transport protein within the plasma membrane, while simple diffusion does not