chemotropismn.
/ˌkiːmə(ʊ)ˈtrəʊpɪz(ə)m/, /ˌkɛmə(ʊ)ˈtrəʊpɪz(ə)m/, U.S. /ˌkimoʊˈtrɑˌpɪz(ə)m/, /ˌkɛmoʊˈtrɑˌpɪz(ə)m/ Biology.
The directional bending or growth of an organism, or part of one, in response to a gradient of concentration of a particular diffusible chemical substance; (also) the directional movement of a motile organism in response to such a gradient (= chemotaxis n.); an instance of either of these responses.Described as positive or negative in respect of whether the direction is towards or away from the region of greater concentration.
ΘΚΠ
the world > life > biology > biological processes > movement > movement in response to stimuli > [noun] > response to chemical
chemotaxis1888
chemotropism1890
chemoreflex1898
chemokinesis1900
chemotactism1903
1890 Amer. Jrnl. Psychol. 3 127 Most remarkable is the chemotropism for oxygen for which most protists have a passion.
1897 Amer. Naturalist 31 719 Positive chemotropism gradually disappears as diffusion renders the concentration slight.
1901 J. Loeb Compar. Physiol. Brain 186 The orientation of an organism by diffusing molecules is termed chemotropism.
1950 M. Bates Nature of Nat. Hist. xi. 167 In some cases roots will grow toward an area of soil with the greatest concentration of some mineral salt or other, showing positive chemotropism.
1994 Sci. News 27 Aug. 135/2 In 1988, Tessier-Lavigne [et al.]..were the first to describe chemotropism at work in the spinal cord.
This entry has been updated (OED Third Edition, December 2008; most recently modified version published online March 2022).
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n.1890