geotropism

ge·ot·ro·pism

G0099700 (jē-ŏt′rə-pĭz′əm)n. See gravitropism.

ge′o·tro′pic (jē′ə-trō′pĭk) adj.

geotropism

(ˌdʒiːəʊˈtrəʊpɪzəm) n (Botany) 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 geotropic adj ˌgeoˈtropically adv

ge•ot•ro•pism

(dʒiˈɒ trəˌpɪz əm)

n. oriented movement or growth of an organism with respect to the force of gravity. [1870–75]

ge·ot·ro·pism

(jē-ŏt′rə-pĭz′əm) The growth of an organism in response to gravity. The downward growth of plant roots is an example of geotropism.

geotropic (jē′ə-trō′pĭk, jē′ə-trŏp′ĭk) adjective

geotropism

Botany. the response of a plant to the force of gravity. — geotropic, adj.See also: Gravity

Thesaurus

Noun

geotropism - an orienting response to gravitytropism - an involuntary orienting response; positive or negative reaction to a stimulus source

Translations

géotropisme

Geotropism

geotropism

[jē′ä·trə‚piz·əm] (botany) Response of a plant to the force of gravity. Also known as gravitropism.

Geotropism

the ability of the organs of plants to assume a certain position under the influence of the earth’s gravity. Geotropism causes the plant’s axial organs to grow vertically: the main root is directed straight downward (positive geotropism), and the main stem is directed straight upward (negative geotropism). If the main stem of the plant is displaced from its typical vertical position because of some external influence, for example, if it is bent or lodged by the wind, the young, still growing part begins to curve and its upper part rises and is again correctly oriented. The tip of the main root, when displaced from its vertical position, curves downward. Geotropic bending is closely linked to growth, and it occurs because in stems that have been displaced from a vertical state the lower side begins to grow more rapidly and the upper side slows down its growth. The unequal rate of growth of the upper and lower sides of horizontal stems is linked with the shifting of auxins to the lower side of the stem or root under the influence of gravity. The parts of plants that have completed their growth are not capable of geotropic bending. Therefore, when plants have been lodged by wind or rain, only the young, growing top of the stem rises. The grasses are an apparent exception: their ganglia retain the ability to renew growth for a long time. When lodging occurs, the lower side of the lower nodes begins to proliferate and raises the part of the stem located above.

In addition to stems growing vertically under the influence of geotropism (orthotropic), there are also horizontally growing stems (plagiotropic). For the most part these are rhizomes and runners (tendrils). A change in the geotropic reaction may occur because of external influences, such as a lower temperature, causing shoots to press close to the ground in alpine and polar plants. The geotropic reaction may also be altered under the influence of certain gases, such as ethylene.

geotropism

[je-ot´ro-pizm] tropism in response to gravity, i.e., either toward or away from the earth; growth influenced by gravity.

ge·o·tax·is

(jē'ō-tak'sis), A form of positive barotaxis in which there is a tendency to growth or movement toward or into the earth. Synonym(s): geotropism [geo- + G. taxis, orderly arrangement]

geotropism

(jē-ŏt′rə-pĭz′əm)n. See gravitropism.

ge′o·tro′pic (jē′ə-trō′pĭk) adj.

geotropism

see GRAVITROPISM.

geotropism

) a plant growth movement that occurs in response to gravity. Thus roots are positively gravitropic (growing downwards), while shoots are generally negatively gravitropic (growing upwards).

geotropism

ge·ot·ro·pism

geotropism

ge•ot•ro•pism

ge·ot·ro·pism

geotropism

Geotropism

geotropism

Geotropism

geotropism

geotropism

ge·o·tax·is

geotropism

geotropism

geotropism

geotropism

Words related to geotropism

noun an orienting response to gravity

Related Words