It is the movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance.
Definition: Chemotaxis is the movement of an organism in response to a chemical stimulus. Bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment.
Function:This is important for bacteria to find food, by swimming toward the highest concentration of food molecules, or to flee from poisons. In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g., migration of neurons or lymphocytes) as well as in normal function and health (e.g., migration of leukocytes during injury or infection).
Chemotaxis is the movement of an organism towards the chemical stimulus. It is helpful for bacteria in finding food. Due to this movement sperm also moves towards the ova during fertilization.