Final answer:
Passive membrane transport includes movement down the concentration gradient and facilitated diffusion, but does not require ATP or move substances from low to high concentration.
Step-by-step explanation:
Passive membrane transport processes include the movement of a substance down its concentration gradient. This means that in passive transport, substances such as gases, lipids, water, glucose, amino acids, and ions move from an area of higher concentration to an area of lower concentration without the need for cellular energy, or ATP. Specifically, passive transport mechanisms are: movement of a substance down its concentration gradient (passive diffusion). Facilitated diffusion through transport proteins, moving substances from areas of high to low concentration without energy use.
Aquaporin-mediated transport of water is exemplified by osmosis, where water moves from an area of low solute concentration to an area of high solute concentration, effectively following its own concentration gradient. However, passive transport does not involve the consumption of ATP or the use of transport proteins to move substances from areas of low to high concentration; those are characteristics of active transport. Passive membrane transport processes include the movement of a substance down its concentration gradient, the use of transport proteins when moving substances from areas of low to high concentration, and the movement of water from an area of low concentration to an area of high concentration.