- A single flagellum can extend from one end of the cell - if so, the bacterium is said to be monotrichous.
- A single flagellum (or multiple flagella; see below) can extend from both ends of the cell - amphitrichous.
- Several flagella (tuft) can extend from one end or both ends of the cell – lophotrichous.
- Multiple flagella may be randomly distributed over the entire bacterial cell - peritrichous.