The kingdom monera are mostly unicellular prokaryotes. Their organisms are the simplest prokaryotes. The characteristics of Monera are as follow.
Cell Type
They are prokaryotic in nature. They are just composed of genetic material. In case of prokaryotic organisms, the nucleus is poorly developed due to the absence of:

Characteristics of Prokaryotic Cell
While in eukaryotes the nucleus is well developed. The poorly developed nucleus has many different names. The list of names is as follow:

Classification of Prokaryotic Nucleus
Cell Wall Composition of Prokaryotes and Eukaryotes
Cell wall of Archaea bacteria and eubacteria is made up of pseudomurein and peptidoglycan. Their composition is as follow Cell Wall.

Prokaryotes and Eukaryotes Cell Wall Composition
Difference Between Prokaryotes and Eukaryotes
The difference between prokaryotes and eukaryotes is as follow in the table.

Composition of Prokaryotes and Eukaryotes
Mode of Nutrition
Mainly mode of nutrition shown by bacteria is heterotrophic. The heterotrophic have further classes as follow:

Mode of Nutrition
Parasitic Mode of Nutrition
It is a relation between two organisms One is host and other is parasite. The parasite takes benefit (food shelter) from host and in return harm the host.
Saprotrophic Mode of Nutrition
It is a relation between a living and non-living organism. Such as bacteria act as decomposer on any dead organic matter (dead body of an organism).
Symbiotic Mode of Nutrition
Relation between living organisms in which both organisms get benefit from each other and no harms come to both sides. E.g., Fungi and algae (Lichens) relationship.
Mode of Reproduction
Reproduction takes place through sexual method. Asexual reproduction is absent. The sexual reproduction is as follow:

Sexual Reproduction in Bacteria
Cell Organelles
Membrane bounded organelles are absent.

Cell Organelles in Prokaryotes
Non-Membranous cell organelle is present “Ribosomes”. There is present only one type of cell membrane due to absence of membrane bounded organelles. Therefore, these prokaryotic organisms are also called as Single Envelop System Organisms

Ribosomal Size of prokaryotes and Eukaryotes
Cyclosis
Movement of cytoplasm around true vacuole is called cyclosis. The movement will be clockwise or anticlockwise. In case of prokaryotes true vacuole is absent, therefore cyclosis movement does not shown by prokaryotic organisms.
Cosmopolitan
Bacteria are found almost everywhere in every type of habitat. So, they are cosmopolitan in nature.
Behavioral Complexity
They are simple in structure (unicellular) but in behavior bacteria are complex due to showing of diverse metabolic activities.