Diffusion and facilitated diffusion are both examples of what type of cellular transport?

Diffusion and facilitated diffusion are examples of passive transport because they involve the movement of substances across a cell membrane without the expenditure of energy. In passive transport, molecules move along their concentration gradient, which means they move from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Diffusion refers to the movement of small, nonpolar molecules, like oxygen and carbon dioxide, directly through the lipid bilayer of the cell membrane. Facilitated diffusion, on the other hand, involves larger or polar molecules that require specific transport proteins to help them cross the membrane. This process still does not require energy, as it relies on the natural tendency of molecules to move down their concentration gradient.

Active transport, in contrast, requires energy to move substances against their concentration gradient. Bulk transport involves the movement of large quantities of materials into or out of the cell via vesicles and also requires energy. Transcytosis is a form of bulk transport that transports large molecules across a cell, often involving endocytosis and exocytosis. Therefore, the characteristic energy independence and movement along concentration gradients categorize both diffusion and facilitated diffusion as passive transport mechanisms.