phototonus

[ foh-tot-n-uhs ]

nounBiology.
  1. the normal condition of sensitiveness to light in organisms or their organs.

  2. the irritability exhibited by cytoplasm when exposed to light of a certain intensity.

Origin of phototonus

1
First recorded in 1870–75; photo- + tonus

Other words from phototonus

  • pho·to·ton·ic [foh-tuh-ton-ik], /ˌfoʊ təˈtɒn ɪk/, adjective

Words Nearby phototonus

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British Dictionary definitions for phototonus

phototonus

/ (fəʊˈtɒtənəs) /


noun
  1. the condition of plants that enables them to respond to the stimulus of light

Origin of phototonus

1
C19: from photo- + Greek tonos tone

Derived forms of phototonus

  • phototonic (ˌfəʊtəʊˈtɒnɪk), adjective

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