Last modified on 14 April 2008, at 18:19


Taxis is the movement of organisms either toward or away from a stimulus, such as light (phototaxis), heat (thermotaxis), chemicals (chemotaxis), gravity (geotaxis), and touch (thigmotaxis). A taxis differs from a tropism in that a taxis implies guided movement in relation to the stimulus, whereas the term tropism only implies growth or turning.