The Student Room Group

examples of taxis/kinesis

Urgh! Have been asked by my teacher to come up with as many examples of tactic and kinetic behaviour in simple organisms as poss. I have no problems with the definitions and can think of a few examples but my problem is, when searching the internet for some more all I could find was degree level gibberish, or weird adverts with people claiming to have telekinetic powers and move stuff with their mind! :mad:
I was wondering if anyone else has some websites that are actually any use? I have spent quite a while looking by now, but I have to confess that I'm a bit of a technophobe at the best of times, :redface: so it could be I'm not using clear enough key words?:confused:
any help appreciated!
Reply 1
Example of kinesis - nondirectional movement in response to a stimulus
Woodlice like damp conditions...if the environment is too dry, they will move more often (although in random directions), until they find a damp environment. They will then move less often to try and stay in that environment. Note that the movement is nondirectional...instead the organism simply moves more, or less in response to a stimulus.

Example of taxis - directional movement in response to a stimulus
When you leave a plant in the window during the summer, it will grow towards the window (i.e. towards the source of light). This is called positive phototaxis because it is a directional movement towards the light (rather than a nondirectional or random movement). Negative phototaxis would be a directional movement away from the light. Hence, taxis can occur both towards or away from a stimulus depending on the organism and stimulus in question.

There are hundreds of examples of taxis....for example, most bacteria are chemotaxic; they movement towards or away from a chemical gradient (e.g. glucose). Thermotaxic would refer to directional movements in response to heat etc etc.
Reply 2
Thanks for the help guys!:smile:
I believe that plants can't show taxis as they require motility. The plant response you describe would be a positive phototropism. Examples of a positive phototaxis would be something like the golden jellyfish in Jellyfish Lake in Palau that follow the arc of the sun during the day so that their symbiotic algae can photosynthesise
Reply 4
I need a clear sentence about animal kinesis
Reply 5
I need a clear sentence about animal kinesis