Which term refers to the self movement of cells or organisms?

The term "motility" specifically refers to the ability of cells or organisms to move independently and actively in their environment. This characteristic is crucial for a variety of biological processes, including the movement of single-celled organisms like bacteria, as well as more complex organisms that move for feeding, reproduction, and avoidance of predators.

Being able to distinguish motility from other options is important. For example, while locomotion also concerns movement, it often refers to the broader category of movement within animals and does not specifically emphasize the cellular level of movement. Migration typically pertains to a specific kind of movement over a distance, often related to seasonal changes or behavioral patterns in animals. Diffusion, on the other hand, is a passive process where particles move from an area of higher concentration to an area of lower concentration and does not involve active movement by cells or organisms. Thus, motility encompasses all forms of active movement, which makes it the most appropriate term in this context.