What is chemotaxis?

Chemotaxis refers specifically to the movement of an organism or cell toward or away from a chemical stimulus. This occurs in response to a concentration gradient of a diffusible chemical, where cells can detect the concentration of the chemical and navigate accordingly. This process is vital for many biological functions, including immune responses, where immune cells move toward sites of infection due to the presence of chemical signals released by pathogens or damaged tissues.

In contrast, the other options describe different types of movement or biological processes that do not relate to the specific definition of chemotaxis. Movement in response to temperature changes describes thermotaxis, and movement induced by physical stimuli does not exclusively involve chemical factors, whereas cellular replication refers to the various processes by which cells divide and replicate, such as mitosis and meiosis.