Simple diffusion across a plasma membrane is called passive transport because it
A) requires transport proteins.
B) requires energy from the cell.
C) does not require energy from the cell.
D) does not require control by the nucleus.
E) moves molecules from low to high concentration.

Question

Quizplus · Accepted Answer

Simple diffusion is passive because a cell does not need to expend energy for it to happen. Small, non-charged molecules, such as oxygen and carbon dioxide, are able to slip between the phospholipid molecules making up the plasma membrane.

Simple Diffusion Across a Plasma Membrane Is Called Passive Transport