Science Definitions

BY: Calen Anderson, 2/3/14, 2nd period.

Tropism:

an orientation of an organism to an external stimulus, as light, especially by growth rather than by movement.

Geotropism

oriented growth with respect to the force of gravity.

Hydrotropism

oriented growth in response to water.

Phototropism

phototropic tendency or growth.

Thigmotropism

oriented growth of an organism in response to mechanical contact, as a plant tendril coiling around a string support.