Question 5 (1 point) All of the following are examples of passive transport except: filtration osmosis endocytosis diffusion

The answer is **endocytosis**.<br /><br />Here's why:<br /><br />* **Passive transport** moves substances across a cell membrane without the cell expending energy. It relies on the natural movement of molecules from areas of high concentration to areas of low concentration (down a concentration gradient).<br /><br />* **Filtration**, **osmosis**, and **diffusion** are all examples of passive transport. They don't require energy from the cell.<br /><br />* **Endocytosis**, however, is a form of *active transport*. It requires the cell to expend energy to engulf materials and bring them inside the cell. It works *against* the concentration gradient in many cases.<br />