Which of the following is NOT a type of transport process where substances cross the membrane without energy input?

The correct response identifies "Active Process" as the option that does not align with the characteristic of transport processes that occur without energy input. Active transport is unique among transport mechanisms because it requires energy, typically derived from ATP, to move substances against their concentration gradient.

In contrast, diffusion, osmosis, and facilitated diffusion are all passive transport processes that enable substances to cross cell membranes without the need for energy. Diffusion refers to the movement of molecules from an area of higher concentration to one of lower concentration until equilibrium is reached. Osmosis specifically deals with the movement of water across a semipermeable membrane, driven by differences in solute concentration. Facilitated diffusion involves the use of carrier or channel proteins in the membrane to assist the movement of specific molecules across, also relying on a concentration gradient without energy expenditure.

Understanding these transport processes is fundamental in nursing as it underlies cellular function, drug delivery, and the principles of fluid balance in the human body.