geotaxis


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Related to geotaxis: thermotaxis

ge·o·tax·is

 (jē′ō-tăk′sĭs)
n.
Movement of a motile organism using the earth's gravity for orientation.

ge′o·tac′tic (-tĭk) adj.
ge′o·tac′ti·cal·ly adv.

geotaxis

(ˌdʒiːəʊˈtæksɪs)
n
(Biology) movement of an organism in response to the stimulus of gravity
ˌgeoˈtactic, ˌgeoˈtactical adj
ˌgeoˈtactically adv

ge•o•tax•is

(ˌdʒi oʊˈtæk sɪs)

n.
oriented movement of a motile organism toward or away from a gravitational force.
[1960–65]
ge`o•tac′tic (-tɪk) adj.
ge`o•tac′ti•cal•ly, adv.

geotaxis

the movement of an organism in response to the force of gravity.
See also: Gravity, Motion
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References in periodicals archive ?
Early-stage larvae, however, showed upward orientation in the water column (negative geotaxis), whereas advanced larvae exhibited downward orientation (positive geotaxis).
Second, zoospores tend to swim upward in a water column (Erwin and Ribeiro 1996), a phenomenon known as negative geotaxis (movement in the opposite direction of gravity), which helps concentrate zoospores from large volumes of leachate.
In addition, the presence of righting reflex posture; negative geotaxis and adult walking reflex were analyzed.
The behavioural basis of larval recruitment in the crab Callinectes sapidus Rathbun: a laboratory investigation of ontogenetic changes in geotaxis and barokinesis.
Individually daily tests in newborn rats were performed according to WHISHAW & KOLB (2005), and included: righting reflex, from the 2nd to the 5th postnatal day (PND); grip strength, from the 14th to the 17th PND; negative geotaxis, from the 7th to the 10th PND.
[32], which assess the manifestation of different reflexes such as surface righting reflex, negative geotaxis, crossed extensor reflex, ear and eyelid twitching, and auditory startle.
Generally, stink bugs exhibit negative geotaxis, moving upward on objects they encounter, and even if on a flat surface such as the ground, they walk to nearby vertical objects and climb upwards.
High risk A hazardous chemical should be chemicals considered as high risk if it is: * a chemical that is carcinogenic * a chemical that is mutagenic, geotaxis or has reproductive hazards * a chemical which affects the central nervous system (which can also affect hearing due to autotoxin effects).
In our cultures of the oomycete Sommerstorffia spinosa, zoospores often concentrate at the water's surface; they probably swim upwards due to an inherent negative geotaxis that has been postulated for all oomycete zoospores (Carlile 1986).
In Nothomyrmecia (and Myrmecia pyriformis [17]) visual navigation across the ground between nest and host tree in dusk and dawn light is essentially crepuscular, and vision is probably less important than geotaxis for navigation on host trees during full darkness [15].
GEOTAXIS A Organism's response to gravity B Earth pressure C Solid part of the earth who am I?