plural noun, Bacteriology.
a group of bacteria, including the green bacteria and purple bacteria, whose energy for growth is derived from sunlight and whose carbon is derived from carbon dioxide or organic carbon.
[foh-tuh-trop-ik, -troh-pik] /ˌfoʊ təˈtrɒp ɪk, -ˈtroʊ pɪk/ adjective, Botany. 1. growing toward or away from the light. 2. taking a particular direction under the influence of light.
[foh-to-truh-piz-uh m, foh-toh-troh-piz-uh m] /foʊˈtɒ trəˌpɪz əm, ˌfoʊ toʊˈtroʊ pɪz əm/ noun, Botany. 1. phototropic tendency or growth. /ˌfəʊtəʊˈtrəʊpɪzəm/ noun 1. the growth response of plant parts to the stimulus of light, producing a bending towards the light source 2. the response of animals to light; phototaxis n. 1899, from German phototropie (1892), from photo- […]
/ˌfəʊtəʊˈtrəʊpɪ/ noun (chem) 1. an alteration in the colour of certain substances as a result of being exposed to light of different wavelengths 2. the reversible loss of colour of certain dyestuffs when illuminated at a particular wavelength
[foh-tuh-toob, -tyoob] /ˈfoʊ təˌtub, -ˌtyub/ noun, Electronics. 1. an with a photosensitive cathode, used like a photocell. /ˈfəʊtəʊˌtjuːb/ noun 1. a type of photocell in which radiation falling on a photocathode causes electrons to flow to an anode and thus produce an electric current