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

Example of type A is found in the negative phototropism of the root of Sinapis.

From Project Gutenberg

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

From Project Gutenberg