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.
- 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.
- 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.
For editors and proofreaders
Line breaks: photo|taxis
Definition of phototaxis in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.