geotropism

[jee-o-truh-piz-uhm]

noun

Biology.

1. oriented growth with respect to the force of gravity.

geotropism

/ ˌdʒiːəʊˈtrɒpɪk, dʒɪˈɒtrəˌpɪzəm /

noun

1. the response of a plant part to the stimulus of gravity. Plant stems, which grow upwards irrespective of the position in which they are placed, show negative geotropism

geotropism

1. The directional growth of an organism in response to gravity. Roots display positive geotropism when they grow downwards, while shoots display negative geotropism when they grow upwards.

2. Also called gravitropism

Other Word Forms

• geotropic adjective
• geotropically adverb

Word History and Origins

Origin of geotropism¹

First recorded in 1870–75; geo- + -tropism

Example Sentences

Then we studied geotropism by observing how our plant grew toward the ceiling, even after we tipped the plant on its side for a few days.

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The relations between vegetable and animal geotropism have been more recently investigated by J. Loeb.

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In whatever direction the primary radicle first protrudes from the seed, geotropism guides it perpendicularly downwards; and the capacity to be acted on by the attraction of gravity resides in the tip.

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Thus I am now observing something about geotropism, and I had no idea a few weeks ago that this would have been necessary.

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It must also be granted that geotropism has a bearing on the problem, since all plants twine upwards, and cannot twine along a horizontal support.

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