[foh-to-truh-piz-uh m, foh-toh-troh-piz-uh m]
- phototropic tendency or growth.
Origin of phototropism
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- 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
Word Origin and History for phototropism
Online Etymology Dictionary, © 2010 Douglas Harper
- Growth or movement of a sessile organism toward or away from a source of light.
- 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.