The movement of the whole organism to an external stimulus is termed

The movement of the whole organism in response to an external stimulus is called taxis. This means that the organism is able to sense the stimulus and move towards or away from it. For example, if a plant is exposed to sunlight, it may exhibit a phototropic movement by growing towards the light source. Similarly, if an insect is exposed to a certain odor, it may exhibit a chemotactic movement by moving towards or away from the source of the odor. Taxis is different from tropism, which refers to the growth or movement of a part of an organism in response to a stimulus, and from nastic movement, which is a non-directional response to a stimulus.