Difference Between Taxis and Tropism l Taxis vs Tropism

The key difference between taxis and tropism is that the taxis refers to the directional movement of animals in response to a stimulus while tropism refers to the directional movement of plants in response to a stimulus.

Organisms show different reactions to internal and external factors. These reactions differ among the species. Plants react in a different way than the animals. Multicellular organisms react differently than unicellular organisms. Taxis and tropism are two such phenomena animals, and plants show respectively. Taxis is a motion or orientation of an animal in response to an external stimulus. On the other hand, tropism is the response of plants towards or away from a stimulus. Both taxis and tropism are directional reactions.


1. Overview and Key Difference
2. What is Taxis
3. What is Tropism
4. Similarities Between Taxis and Tropism
5. Side by Side Comparison – Taxis vs Tropism in Tabular Form
6. Summary

What is Taxis?

Taxis is a process that shows directional movement or orientation of animals in response to an external stimulus. The whole body shows movements towards or away from the stimulus. Unicellular organisms, mainly protozoans show distinct taxis responses to different stimuli. Based on the type of stimulus, taxis are different types namely chemotaxis, phototaxis, etc.  Chemotaxis is the directional movement of an animal in response to a chemical. Chemotaxis can be either positive or negative. If the movement is towards the chemical, it is positive chemotaxis. The opposite is negative chemotaxis. Movement of ants toward sugar is positive chemotaxis while movement of mosquitoes away from mosquito coil smell is negative chemotaxis.