What are the three parts of bacterial flagellum?

Filament, hook and basal body

The correct answer is Option (4) – Filament, hook and basal body

Here's a breakdown of the different parts:

• Filament: This is the long, thread-like structure that extends outwards from the cell and is visible under a microscope. It's made of a protein called flagellin and acts like a propeller, rotating to propel the bacterium.
• Hook: This short, curved structure connects the filament to the basal body. It acts as a universal joint, allowing the filament to rotate in different directions.
• Basal body: This is the embedded portion of the flagellum located within the cell membrane and cell wall. It's a complex structure that acts as a rotary motor, powered by the flow of ions across the cell membrane. The basal body uses the energy to spin the hook and filament, generating thrust for the bacterium.