Question

Prokaryotic flagellum consists of
A) fiber enclosed by protein-membrane
B) fiber enclosed by a unit membrane
C) Helically arranged protein molecules
D) membrane-enclosed 7+2 microtubular structure

Answer 1

Hint:Flagellum is present in both prokaryotes and eukaryotes. Flagella are filamentous protein structures present on the cell surface that provide the swimming movement for most motile prokaryotes.

Complete Answer:
Flagellum is a long, threadlike structure, a whip-like extension of certain cells or unicellular organisms that functions as an organ of locomotion. The flagellum of prokaryotes consists of three parts, filament, hook, and the basal body.
>Filament:-Filament is the longest portion of the flagellum. Filament extends from the cell surface to the tip. It is a hollow, rigid cylinder, made up of single protein flagellin. The protein molecules are helically arranged in the filament.
>The basal body:-The basal body is the portion of flagellum which is embedded in the cell. It is a very complex part of a flagellum. It is made up of 2- 4 rings connected to a central rod.
> Hook:-It is a short and curved flexible segment that links the filament to its basal body.

Hence, the correct answer is ‘C’. Prokaryotic flagellum consists of Helically arranged protein molecules.

Note:Fimbriae and Pili are short, hair-like structures on the surfaces of prokaryotic cells. Like flagella, they are composed of protein. Fimbriae are shorter than flagella and slightly smaller in diameter. Fimbriae are called the organ of adhesion. Fimbriae are generally not related to motility and can be found both in motile as well as in nonmotile organisms.