Question

Peptidoglycan is characteristic constituent of cell wall in
(A) Archaebacteria and Eukaryotes
(B) Eubacteria and unicellular Eukaryotes
(C) Bacteria and Cyanobacteria
(D) Monera and Protista

Answer 1

Peptidoglycan is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall.Peptidoglycan is also known as murein.

Complete answer:
Based on the type of cell wall and development of nucleus, the microorganisms are classified into two broad categories: prokaryotes and eukaryotes. The microorganisms which lack a well- organized membrane bound nucleus and cell wall were considered as prokaryotes, whereas the eukaryotes showed a distinct cell wall with developed nuclear envelope. Mostly the unicellular lower level microorganisms come under the category of prokaryotes. Both the bacteria and cyanobacteria are the prokaryotes and have many similarities. Both of them do not have well developed cell organelles and entails nucleoid rather than true nucleus. Also, they exhibit a saprophytic form of life and show similar types of cell division. Peptidoglycans are also referred to as murein. These are a group of polymers that help in the development and establishment of the cell wall of a wide range of bacteria. The peptidoglycan plays an important role in bacteria as it provides strength to their outer structures. Peptidoglycans are also helpful for asexual reproduction of bacteria, particularly in binary fission where the bacteria they divide into two distinct cells and the peptidoglycan assists in proper growth of these cells.Peptidoglycan is the characteristic component present in the cell wall of both bacteria and cyanobacteria.

Hence,the correct answer is option (C).

Note: The peptidoglycans are mainly composed of two recurring amino sugars which are N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), and a peptide of numerous amino acids is connected to every NAM units. Moreover, the Gram positive bacteria exhibit a thick peptidoglycan coat and have no lipid membrane, at the same time the Gram negative bacteria exhibit a thin peptidoglycan coat and have an external lipid membrane.