I believe that it is form the Paleozoic era
A stimulus is an event or activity that can produce a physiologic response.
Same as your given meaning above, "to goad, urge or prod" is to induce or elicit a response from something. And just like the action of a stimulus, it can provoke a reaction. This can happen inside or outside of the body.
Answer:
A cell organelle that helps process and package proteins and lipid molecules.
It is the first option. Atmospheric nitrogen is very stable so there fore hard to react with. But bacteria contain molecules that can break the bond of nitrogen.
Salt absorbs moisture and it does not freeze