[foh-tot-n-uh s] /foʊˈtɒt n əs/

noun, Biology.
the normal condition of sensitiveness to light in organisms or their organs.
the irritability exhibited by cytoplasm when exposed to light of a certain intensity.
the condition of plants that enables them to respond to the stimulus of light

phototonus pho·tot·o·nus (fō-tŏt’n-əs)
The state of being sensitive to or irritated by light.
pho’to·ton’ic (fō’tə-tŏn’ĭk) adj.


Read Also:

  • Phototopography

    [foh-toh-tuh-pog-ruh-fee] /ˌfoʊ toʊ təˈpɒg rə fi/ noun 1. topographical surveying employing photogrammetric methods. /ˌfəʊtəʊtəˈpɒɡrəfɪ/ noun 1. the preparation of topographic maps from photographs

  • Phototoxic

    /ˌfəʊtəʊˈtɒksɪk/ adjective 1. (of cosmetics, skin creams, etc) making the skin hazardously sensitive to sunlight phototoxic pho·to·tox·ic (fō’tō-tŏk’sĭk) adj. Rendering the skin susceptible to damage by light. Used of certain medications. pho’to·tox·ic’i·ty (-tŏk-sĭs’ĭ-tē) n.

  • Phototoxin

    [foh-tuh-tok-sin] /ˈfoʊ təˌtɒk sɪn/ noun 1. Biochemistry. a plant causing an allergic reaction when touched or eaten by a susceptible person or animal subsequently exposed to sunlight.

  • Phototransistor

    [foh-toh-tran-zis-ter] /ˌfoʊ toʊ trænˈzɪs tər/ noun, Electronics. 1. a that amplifies current induced by photoconductivity. /ˌfəʊtəʊtrænˈzɪstə/ noun 1. a junction transistor, whose base signal is generated by illumination of the base. The emitter current, and hence collector current, increases with the intensity of the light phototransistor (fō’tō-trān-zĭs’tər) A transistor that regulates current or switches it […]

Disclaimer: Phototonus definition / meaning should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. All content on this website is for informational purposes only.