Answer:
Bacterial flagella is the external structure that is thin, long and filamentous. It is attached to the cell wall of the bacteria which helps in the locomotion of the bacteria. It has three parts a filament, hook and basal body. The basal body is incorporated in the cell membrane.
A flagellum is made up of a protein called flagellin. It is a rigid protein and helps in making the hollow core of the filament by assembling together to form a structure which is cylindrical in shape.
The organization of flagella on bacterial cells is helpful in the identification of bacterial species. Mostly 4 type of organization of flagella is present on bacterial cell that are monotrichous, amphitrichous, lophoyrichous and perithrichous.
In monotrichious bacteria, only one flagella is present on one side, in amphitrichous both side of the cell have an equal amount of flagella. Lophotrichous bacteria have a group of flagella at one side of the cell and amphitrichous bacteria have many flagella distributed equally on its cell.
