Tropism

4. Biology any behavior of a living organism that results from an external or internal stimulus.
7. A change from inside an organism.
9. Respose to negative stimuli.
10. the cell substance between the cell membrane and the nucleus, containing the cytosol, organelles, cytoskeleton, and various particles.
12. something that incites to action or exertion or quickens action, feeling, thought, etc.
13. the growth or turning of plant roots toward or away from moisture.
14. the turning or bending of a plant or other organism in response to a touch.
16. the growth of the parts of plants with respect to the force of gravity. The upward growth of plant shoots is an instance of negative version ; the downward growth of roots is positive version.
17. A change coming from outside an organism.

1. a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid. (one of the cell's organelles)
2. the pressure exerted on a plant cell wall by water passing into the cell by osmosis Also called hydrostatic pressure.
3. (of a plant, leaf, or flower) become limp through heat, loss of water, or disease; droop.
5. the orientation of a plant or other organism in response to light, either toward the source of light ( positive ) or away from it ( negative ).
6. an orientation of an organism to an external stimulus, as light, especially by growth rather than by movement.
8. Membrane the semipermeable membrane enclosing the cytoplasm of a cell.
11. Response to positive stimuli.
15. something that incites to action or exertion or quickens action, feeling, thought, etc.: