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In biology the term behavior refers to the means by which living things respond to their environments. At first glance, this might seem to encompass only animal behavior, but, in fact, plants display observable behavior patterns as well. One of the principal manifestations of plant behavior is tropism, a response to a stimulus that acts in a particular direction, thus encouraging growth either toward or away from that stimulus. Behavior in plants is primarily a matter of response to stimuli, which may be any one of a variety of influences that derive either from inside or outside the organism....

