Which term defines mechanisms that move materials across the cell membrane without using cellular energy?

The correct term that defines mechanisms moving materials across the cell membrane without utilizing cellular energy is "Passive Processes." This concept pertains to the movement of substances through the cell membrane driven by concentration gradients, where molecules naturally move from areas of high concentration to areas of low concentration. Since this process does not require energy input from the cell, it allows for efficient movement of substances, such as gases or small molecules, into and out of the cell.

In biological systems, passive processes can include processes like diffusion and osmosis, where substances travel through the membrane until equilibrium is reached. Understanding this concept is crucial for grasping how nutrients and other compounds distribute themselves within the body, which is vital for maintaining cellular health and function.