Any Process That Results in a Change in State or Activity of a Cell or an Organism (in Terms of Movement Secretion Enzyme Production Gene Expression Etc.) As a Result of a Stimulus. the Process Begins with Detection of the Stimulus and Ends with a Change in State or Activity or the Cell or Organism.
Enables the Facilitated Diffusion of an Ion (by an Energy Independent Process) by Passage Through a Transmembrane Aqueous Pore or Channel Without Evidence For a Carrier Mediated Mechanism. May Be Either Selective (it Enables Passage of a Specific Ion Only) or Non Selective (it Enables Passage of Two or More Ions of Same Charge But Different Size).