The attraction or repulsion of certain cells to chemicals in their environment is called chemotaxis.

Here's a breakdown:

* Chemo-: refers to chemicals

* -taxis: refers to movement or directed motion

Types of Chemotaxis:

* Positive Chemotaxis: Cells move towards a chemical attractant.

* Negative Chemotaxis: Cells move away from a chemical repellent.

Examples of Chemotaxis:

* Bacteria: Bacteria use chemotaxis to find food sources and avoid harmful substances.

* Immune cells: White blood cells use chemotaxis to move to sites of infection.

* Sperm cells: Sperm cells use chemotaxis to navigate towards the egg.

Chemotaxis is a crucial process in many biological functions, including development, immunity, and wound healing.