The movement response of an organism to an external stimulus, such as heat or light
The involuntary movement of an organism activated by an external stimulus wherein the organism is either attracted to or repelled from the outside stimulating influence An example is heliotropism, the movement wherein plants turn toward the sun
an affinity for or the tendency to move toward a specific target; the attraction of a virus or other microorganism to a particular type of cell or host tissue (e g , M-tropic HIV preferentially infects macrophages)
An attraction to something; more specifically, the tendency of a virus to preferentially infect a particular host tissue or cell Viral tropism is determined in part by the interaction of structures on the viral envelope (see Envelope, gp41, gp160, gp120) with host cell receptor sites (see Receptor, CD4, CCR5, CXCR4)
{i} orientation of an organism usually involving growing in positive or negative response to stimuli (Biology)
the turning of an organism in response to a stimulus, either towards or away from the stimulus
an involuntary orienting response; positive or negative reaction to a stimulus source
Involuntary orientation by an organism or one of its parts that involves turning or curving by movement or by differential growth and is a positive or negative response to a source of stimulation