Sensory Reception

Stimulus- delectable change in internal or external environment 

Stimuli detected by Receptors

Receptors transform the energy of the stimuli into a form of energy that can be processed by the organism

A response is carried out by the effector

Stimulus ----- Receptor ------ Coordinator ------ Effector ------ Response                                               (CNS)

Taxes

Taxis- response direction determined by direction of stimulus 

Organisms responds by moving towards favorable stimulus and away from unfavorable                                                            (Positive Taxis)                     (Negative Taxis)

e.g. Earthworms move away from light (Negative phototaxis)

Kineses

Organisms does not move towards or away from stimulus

The more unpleasant the stimulus, the more rapidly it moves and changes direction 

The goal is to bring the organisms back into  favorable conditions

e.g. woodlice move more rapidly in dry conditions in order to prevent water loss

Tropisms

Plant movement in response to a directional stimulus

e.g. plant shoots grow towards sun

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