What characterizes taxis in terms of movement?

The movement of taxis is characterized by its directional response to environmental stimuli. Specifically, taxis involves organisms moving toward or away from a particular stimulus, such as light, heat, or chemicals. This behavior enables organisms to optimize their chances of survival by navigating towards beneficial environments or resources and away from harmful ones.

For instance, phototaxis describes an organism's movement toward light, while chemotaxis refers to movement towards or away from chemical substances. This is a key feature of taxis and distinguishes it from other types of movement, such as random movement, which lacks directional bias. The other options do not accurately describe taxis, as they either imply random, circular, or constant-speed movement that does not involve a directed response to stimuli.