Share this entry

Share this page

phototaxis

Line breaks: photo|taxis
Pronunciation: /ˌfəʊtəʊˈtaksɪs
 
/

Definition of phototaxis in English:

noun (plural phototaxes)

[mass noun] Biology
The bodily movement of a motile organism in response to light, either towards the source of light ( positive phototaxis) or away from it ( negative phototaxis). Compare with phototropism.
Example sentences
  • Wild-type flies showing normal phototaxis consistently moved towards the light to end up in the last tube by the end of the trial.
  • Namely, two rhodopsins that absorb in different spectral bands and optimally function at different intensity ranges generate two photoreceptor currents that control flagella movement during phototaxis.
  • Far-red or red background lights irradiated vertically from above drastically inhibited phototaxis toward red light or far-red light, respectively.

Derivatives

phototactic

1
adjective
Example sentences
  • From a screen of 18,500 mutagenized flies, 171 phototactic mutants were recovered of which 15 appear to be specifically defective in synaptic transmission on the basis of the results of electroretinogram recordings.
  • Lebert and Hader observed a curious phototactic phenomenon in eyeless mutants of Euglena, i.e. it swam perpendicularly with respect to the incident light, namely, diaphototaxis.
  • Most unicellular flagellate algae are phototactic, i.e., capable of orientation with respect to the direction of light.

Definition of phototaxis in:

Share this entry

Share this page

 

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day tenebrous
Pronunciation: ˈtɛnɪbrəs
adjective
dark; shadowy or obscure