Dictionary.com

phototropism

[ foh-to-truh-piz-uhm, foh-toh-troh-piz-uhm ]
/ foʊˈtɒ trəˌpɪz əm, ˌfoʊ toʊˈtroʊ pɪz əm /
Save This Word!

noun Botany.
phototropic tendency or growth.
QUIZ
CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?
There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?
Question 1 of 7
Which sentence is correct?

Origin of phototropism

First recorded in 1895–1900; photo- + -tropism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use phototropism in a sentence

British Dictionary definitions for phototropism

phototropism
/ (ˌfəʊtəʊˈtrəʊpɪzəm) /

noun
the growth response of plant parts to the stimulus of light, producing a bending towards the light source
the response of animals to light; phototaxis

Derived forms of phototropism

phototropic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for phototropism

phototropism
[ fō-tŏtrə-pĭz′əm ]

The growth or movement of a fixed organism toward or away from light. In plants, phototropism is a response to blue wavelengths of light and is caused by a redistribution of auxin from the illuminated side to the darker side of the shoot, resulting in quicker growth on the darker side and bending of the shoot toward the source of light. Certain sessile invertebrates also exhibit phototropism.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK