Response - Response to Stimuli: Survival and Response Flashcards
Which organisms will a selection pressure favour?
Those with more appropriate responses.
What is chemotaxis?
A directional response to chemicals/ions.
What is hydrotaxis?
A directional response to water.
What is phototaxis?
A directional response to light.
What is thigmotaxis?
A directional response to touch.
What is a taxis?
A directional response to a directional stimulus.
What is a kinesis?
A response to a changing stimulus characterised by a change in the amount of activity.
Give 3 characteristics of kineses.
Non-directional
Change of speed
Change in rate of change of direction
What will an organism showing a kinesis do if it crosses a sharp dividing line from a favourable environment and an unfavourable environment? Why?
Increase its rate of turning to raise its chances of a quick return to a favourable environment.
Name two different types of communication within organisms.
Hormonal
Nervous
Which is faster; hormonal or nervous communication?
Nervous
Summarise the sequence of how organisms formulate a response.
Stimulus –> receptor –> coordinator –> effector –> response
