Question

The uniqueness of bacterial flagella is that it is
A. Mono fibrillar
B. Has a 9+2 arrangement
C. Multi fibrillar
D. Has 2+9 arrangement

Answer 1

The flagellum is the rod-like structure of bacteria that is present in the bacteria. This flagellum helps in the movement of the bacteria.

Complete answer:
The flagellum of the bacteria is made up of 9 pairs of microtubules. This surrounds the two centrally placed singlet microtubules. Hence, the structure is denoted as 9 + 2 but no 2 + 9.
This feature is generally seen in the eukaryotic flagellum.
The prokaryotic flagellum is made up of parts – the filament, the hook, and the basal body. The filament is composed of flagellin protein. This protein is arranged in the flagella in a helix-like structure.
Thus, we can say prokaryotic flagellum has a single fibril but eukaryotic flagellum has 9 + 2 fibril arrangement.

Thus, for bacterial flagella, the correct answer is option A. mono fibrillar.

Note: The bacteria can be divided into many classes according to the presence of flagella. These are as follows –
Monotrichous – only one flagellum is present.
Amphitrichous – two flagella are present, each on either side of the bacterial cell.
Lophotrichous – a branch of flagella is present in one side of the bacterial cell.
Peritrichous – numerous flagella are present in the bacterial cell.
Atrichous – no flagellum is present.