Phototropism

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Phototropism \Pho*tot"ro*pism\, n. [Photo- + Gr. ? to turn.]
     1. (Plant Physiol.) The tendency of growing plant organs to
        move or curve under the influence of light. In ordinary
        use the term is practically synonymous with
        {heliotropism}.
        [Webster 1913 Suppl.]


  
     2. (Microbiology) exhibiting movement in a direction toward
        ({positive phototropism}) or away from ({negative
        phototropism}) a source of light.
        [PJC]

From WordNet (r) 2.0 [wn]:

  phototropism
       n : an orienting response to light