Responses to Stimuli: Kineses Flashcards
what is a kinesis?
a kinesis is a form of response in which the organism does not move towards/away from the stimulus, instead it changes its movement speed and the rate at which it changes direction
what happens if an organism crosses a sharp dividing line between a favourable and an unfavourable environment?
its rate of turning increases
if an organisms rate of turning increases, what does this raise its chances of?
raises its chances of a quick return to a favourable environment
if an organism moves a considerable distance into an unfavourable environment what happens to its rate of turning?
its rate of turning may slowly decrease
if an organisms rate of turning decreases, what direction(s) does it move in?
in long, straight lines before it turns (often very sharply)
as an example, what 2 factors do not produce a clear gradient from one extreme to another?
temperature and humidity
name an organism in which kinesis occurs in?
woodlice
in which condition(s) do woodlice lose water from their bodies?
dry conditions
what happens when woodlice move from a damp area into a dry area?
woodlice move more rapidly and change direction more often
if the woodlice move faster and change direction more often, what does this increase their chances of?
increases their chances of moving back into the damp area
what happens if the woodlice are in the damp area?
woodlice slow down and change direction less often
what does it mean if the woodlice slow down and change direction less often in a particular area?
more likely to stay within the damp area
if after some time spent changing direction rapidly the woodlice are in the damp area, what happens to their behaviour?
they move rapidly in straight lines
how does the woodlice moving rapidly in straight lines in a damp area, increase their chances of survival?
increases their chances of moving through the dry area and into a new damp area
which conditions prevents woodlice from drying out, and therefore increasing their chances of survival?
if the woodlice spend more time in favourable damp conditions than in unfavourable dry conditions
