phototropism

[ foh-to-truh-piz-uhm, foh-toh-troh-piz-uhm ]

noun

, Botany.

1. phototropic tendency or growth.

phototropism

/ ˌfəʊtəʊˈtrəʊpɪzəm /

noun

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

phototropism

/ fō-tŏt′rə-pĭz′əm /

1. 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.

Derived Forms

• ˌphotoˈtropic, adjective

Word History and Origins

Origin of phototropism¹

First recorded in 1895–1900; photo- + -tropism

Example Sentences

“If the ground is very firm and stable, and it’s just as compacted on this side as it is on the other side, chances are it’s phototropism” — bending toward the light.

From Seattle Times

Most plants show phototropism -- the ability to grow toward a light source.

From Science Daily

If the tree has grown at a slant all its life, it’s probably because of phototropism, Brosius says.

From Washington Post

Here, microtubule organization patterns the deposition of cellulose, the prime constituent of cell walls, thus controlling the ability of plants to grow in the direction of light, or phototropism.

From Science Magazine

Thus the term phototropism means a turning or orientation brought about by means of light.

From Project Gutenberg