Phototaxis /(?)/

Pho·to·tax·is

Phototaxis

n.
  1. The influence of light on the movements of low organisms, as various infusorians, the zoospores of certain algæ, etc.; also, the tendency to follow definite directions of motion or assume definite positions under such influence. If the migration is toward the source of light, it is termed positive phototaxis; if away from the light, negative phototaxis. (Biol.)