phototropism


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phototropism

 [fo-tot´ro-pizm]
1. tropism of an organism in response to light; it may be either positive (toward the light) or negative (away from the light).
2. change of color produced in a substance by the action of light. adj., adj phototrop´ic.

pho·tot·ro·pism

(fō-tot'rō-pizm),
Movement of a part of an organism toward (positive phototropism) or away from (negative phototropism) the stimulus of light. Compare: phototaxis.
[photo- + G. tropē, a turning]

phototropism

/pho·tot·ro·pism/ (fo-tot´rah-pizm)
1. the tendency of an organism to turn or move toward or away from light.
2. color change produced in a substance by the action of light.phototrop´ic

phototropism

(fō-tŏt′rə-pĭz′əm, fō′tō-trō′-)
n.
Growth or movement of a sessile organism toward or away from a source of light.

pho′to·tro′pic (fō′tə-trō′pĭk) adj.

pho·tot·ro·pism

(fō-tot'rŏ-pizm)
Movement of a part of an organism toward (positive phototropism) or away from (negative phototropism) the stimulus of light.
Compare: phototaxis
[photo- + G. tropē, a turning]

phototropism

a bending growth movement of parts of a plant in response to a light stimulus. The movement produced by unequal growth is due to differences in AUXIN concentration. For example, most seedlings are positively phototropic, growing towards a light stimulus, because there is a greater concentration of auxin on the side furthest away from the light, giving greater growth on this side. Roots, on the other hand, are often negatively phototropic, growing away from a light source.

phototropism 

Reaction of certain plants and animals to move towards (positive phototropism) or away from (negative phototropism) a source of light.

phototropism

1. the tendency of an organism to turn or move toward (positive phototropism) or away from (negative phototropism) light.
2. change of color produced in a substance by the action of light.
References in periodicals archive ?
This helped the scientists confirmed that the hormone auxin definitely is the substance that drives phototropism.
Phototropisms may be either positive, in the case of stems, or negative, in the case of roots.
Positive phototropism is growth of plants toward light.
Their urban projects (they already have at least four distinguished houses under their belt) tend to exploit specifics of orientation, perhaps most flamboyantly expressed in Mosaic House (AR August 2007) that mimicked phototropism to exploit high-level daylight.
Auxins have been found responsible for phototropism, geotropism, and apical dominance.
A different method of some vines, mostly adventitious root climbers, is to use a process called skototropism or negative phototropism in which they grow toward dark surfaces until they find a potential support structure (Hegarty, 1991).
Hatching rate was calculated by counting the number of nauplii per spawn sample through collection by positive phototropism.
Indole-3-acetic acid (IAA) is the only active auxin found in plants today and is involved in numerous physiological processes in plants, including cellular elongation, phototropism, gravitropism, apical dominance, root initiation, ethylene production, fruit growth, sex expression, and weed control.
phototropism A growth movement in plants in response to light.
varia showed a clear tendency to negative phototropism, with preference for surfaces not exposed to the light in horizontally-positioned opaque collectors.
Light-responsive behaviors such as siphon contraction [1], phototropism [2], and gamete release [3, 4] have been described in several ascidian species.