In the Monera Kingdom, living organisms are considered to be prokaryotic, that is: non-karyotek. Other differences between prokaryotes and eukaryotes consist in the former having a single chromosome, consisting of a single circular DNA molecule, the genome being organized in this.
However, this classification is increasingly out of favor as more in-depth analyzes have been made, realizing that these individuals could be divided into two distinct kingdoms (the same happened with the protists).
Thus, members of the Monera Kingdom came to be considered the Archaea and Bacteria kingdoms, with the other living beings divided into the Animalis, Fungi, Plantae, Archezoa, Protista and Chromista kingdoms – the last three encompass the organisms that were once belonging to the kingdom Protist. This classification is called the eight-realm system.
There is also another way of evaluating living beings, called the three-domain system, in which they are divided into the Arquea, Bacteria and Eukarya domains. These differ from those in ribosomal RNA composition, cell wall structure, and metabolism.
The differences between the Arquea and Bacteria kingdoms consist in the fact that the former do not have peptidoglycans in the cell wall, they are able to produce methane as a waste of metabolism and are able to survive in extreme environments of life, such as volcano craters and extremely saline regions.
Bacteria are represented by bacteria, cyanobacteria, rickettsiae (tiny intracellular parasites!) and mycoplasma (the smallest organisms capable of self-replicating). As for bacteria, the plasma membrane is covered by the cell wall and, in some species, there is the presence of a capsule. The cell wall is what helps in the classification of bacteria, as they are responsible for the susceptibility to diseases and staining using the Gram method. Gram-positives are sensitive to sulfa and have a wall formed basically of a single layer, staining violet in the Gram stain; Gram-negatives are sensitive to penicillin, have a two-layered wall and turn pink when stained. The latter are considered more dangerous as their walls are less permeable to antibiotics.
By Mariana Araguaia
Graduated in Biology
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Would you like to reference this text in a school or academic work? Look:
ARAGUAIA, Mariana. "Monera Kingdom or Archaea and Bacteria Kingdoms? Realms or Domains?"; Brazil School. Available in: https://brasilescola.uol.com.br/biologia/reino-monera-ou-reinos-archaea-bacteria-reinos-ou-.htm. Accessed on June 27, 2021.