phototaxis


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phototaxis

 [fo″to-tak´sis]
taxis of cells and microorganisms under the influence of light. adj., adj phototac´tic.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

pho·to·tax·is

(fō'tō-tak'sis),
Reaction of living protoplasm to the stimulus of light, involving bodily motion of the whole organism toward (positive phototaxis) or away from (negative phototaxis) the stimulus. Compare: phototropism.
[photo- + G. taxis, orderly arrangement]
Farlex Partner Medical Dictionary © Farlex 2012

phototaxis

(fō′tō-tăk′sĭs)
n.
The movement of an organism or a cell toward or away from a source of light.

pho′to·tac′tic (-tăk′tĭk) adj.
pho′to·tac′ti·cal·ly adv.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

pho·to·tax·is

(fō'tō-tak'sis)
Reaction of living protoplasm to the stimulus of light, involving bodily motion of the whole organism toward (positive phototaxis) or away from (negative phototaxis) the stimulus.
Compare: phototropism
[photo- + G. taxis, orderly arrangement]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

phototaxis

the movement of a whole organism in response to a directional light stimulus. For example, movement of unicellular algae or fruit flies towards a source of light is positive phototaxis, while movement away from light if the stimulus is too strong is negative phototaxis.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
Ontogeny of phototaxis and metamorphic competence in larvae of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia).
imbecillis that had completed their parasitic phase with chironomids (what I referred to as post-chironomid larvae) exhibited negative phototaxis only in the presence of water that had been modified by U.
Spudich, "Two rhodopsins mediate phototaxis to low- and high-intensity light in Chlamydomonas reinhardtii," Proceedings of the National Academy of Sciences of the United States of America, vol.
Males have obvious phototaxis. The second generation of eggs begins to hatch in the middle of July, with pupation beginning in mid to late August and adult emergence in early September.
However, a common misunderstanding is that this attraction represents a positive phototaxis. Contrary to this belief, Thompson (1917), Verheijen (1958), Mazokhin-Porshnyakov (1969), Janzen (1983), and more recently Nowinszky (2003) observed that insect attraction to lights is the result of navigational confusion.
These orchids had adapted by pointing upward to seek sunlight (positive phototaxis) and opposing gravity.
Escape behavior mediated by negative phototaxis in the scorpion Paruroctonus utahensis (Scorpiones, Vaejovidae).
Both species use a statocyst to detect changes in gravity (geotaxis) and a photoreceptor to detect changes in light (phototaxis).