单词	phototaxis
释义	phototaxis /ˌfəʊtəʊˈtaksɪs / 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. Derivatives phototactic adjective ... 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.
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