Question

The function of mesosome in prokaryotes is :
A) Aerobic respiration
B) Cell wall formation
C) Both a & b
D) Nitrogen- fixation.

Answer 1

Mesosome is a special invaginated structure, formed by the infoldings of the plasma membrane into the cell wall. These are mostly in the form of lamellae, tubules and vesicles.

Complete Answer:
Prokaryotes are single-celled microorganisms & are known to be the earliest on earth. They include Archaea & Bacteria. The photosynthetic prokaryotes include cyanobacteria; these perform photosynthesis.
A prokaryotic cell consists of one membrane and therefore, all the reactions occur within the cytoplasm. They can either be free-living or parasites.
Usually, mesosomes are found associated with the nuclear areas or near the sites of cell division. They are absent in eukaryotes.
Option a) : Aerobic respiration - Prokaryotes may perform aerobic (oxygen-requiring) or anaerobic (non-oxygen-based) metabolism. Prokaryotes that need oxygen in order to metabolize are called obligate aerobes. Mesosomes also carry the enzymes for aerobic respiration and increase the surface area for the same. Thus, this option is Correct.
Option b) : Cell wall formation - The main uses / roles of mesosomes are :-
->Distribution of daughter cells.
->Replication of DNA.
->Synthesis of cell wall.
->Respiration
->Secretions.
Thus, this option is also Correct.
Option c) Both a & b - Since, this option includes both the correct options, it is the most Correct one.
Option d) Nitrogen fixation - Mesosomes do not help in nitrogen fixation, in any way. Thus, this option is incorrect.

Hence option ‘C’ is the correct answer.

Note: Mesosomes also play a role in reproduction. During binary fission, a mid-wall is formed, which results in the formation of two cells. A prokaryotic cell lacks certain organelles like endoplasmic reticulum, Golgi bodies & mitochondria.