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Related to geotaxis: thermotaxis


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.


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


(ˌdʒi oʊˈtæk sɪs)

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


the movement of an organism in response to the force of gravity.
See also: Gravity, Motion
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References in periodicals archive ?
In addition, the presence of righting reflex posture; negative geotaxis and adult walking reflex were analyzed.
In contrast, temperature had no effect on the alteration of refuge use or geotaxis observed in infected gammarids.
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.
It has been suggested that this behavior is caused by positive phototaxis, yet some other studies proposed negative geotaxis (Yano & Ogawa 1977, Sasaki & Shepherd 1995, Leighton 1989).
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 addition, all behaviors of experimental animals were determined via a battery test consisting of negative geotaxis, hot-plate, rotarod, open-field, elevated plus-maze, Morris water maze, and social behavior tests.
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).
GEOTAXIS A Organism's response to gravity B Earth pressure C Solid part of the earth who am I?
However, the impact of interventions on health span is commonly evaluated by means of motor performance test such as spontaneous motor activity and the geotaxis test.
The following reflex tests were assessed in all pups from each litter: surface righting reflex (a normal ventral position assumed after the animal is placed on its back, observed for 15 s, postnatal days 2 to 7), negative geotaxis (to turn at least 90, after being placed face-down in a platform inclined at 45; the maximum time allowed for the pup to turn was 30 s, PD 7 to PD 12), and grasping reflex (registering the day of absence of involuntary bending of the fingers in response to tactile stimulation on the palm, PD2 to PD12).