In bacteria, the flagellum is primarily associated with which function?

• A. Reproduction
• B. Locomotion
• C. Nutrient storage
• D. Cell wall synthesis

Answer: (B)

The concept being tested is that the bacterial flagellum is used mainly for movement. The flagellum is a whip-like appendage that rotates like a propeller, powered by the proton motive force across the membrane, allowing the cell to swim through liquid. This motility enables the bacterium to move toward favorable environments or away from harmful ones (chemotaxis). Reproduction, nutrient storage, and cell wall synthesis are handled by other cellular processes and structures, not by the flagellum. So, the flagellum's primary role is locomotion.