Many centuries ago, organisms were classified according to their complex structure. The 5 kingdoms of living things includes the eukaryotic Protista, Fungi, Plantae and Animalia. You can find out more information on characteristics of Fungi. The single celled organisms like bacteria were placed under the kingdom Monera. After a deep study of Monera kingdom characteristics, the kingdom was divided into two groups Archaea and Bacteria. This classification of living things was under the three domain system of taxonomy that was established in 1991. The third domain included the Eukaryote group. The common names used for Monera sometimes include Prokaryota or Prokaryotae. This classification was under the three domain system of taxonomy that was established in 1991.
Characteristics of Monera
The following points related to Monera characteristics will help you understand the kingdom of classification better.
• Monera are about 1 micrometer in size and complex as living molecules.
• The Monera cell structure is mostly unicellular and some organisms that form groups or filaments.
• These organisms are the simplest prokaryotic cell structures.
• The Monera cell structure lacks nuclei and many other cell organelles.
• They have a cell wall made of polysaccharides with polypeptide cross links with a chemical called peptidoglycan.
• They lack enclosed sub-cellular organelles like mitochondria and only have ribosomes.
• The genetic material DNA is contained in the cytoplasm called nucleoid.
• Many bacterial species contain rings of DNA called plasmids.
• The cytoplasm is enclosed by plasma membrane that lies beneath the cell wall.
• The plasma membrane is made up of lipids and proteins.
• Some Monera have hair like pilli for adhesion or tail-like flagella for locomotion.
• The source of nutrition for these organisms is usually photosynthesis or chemosynthesis.
• The Monera characteristics also include the shape of the cell that includes round (cocci), rod-like (bacilli) or spiral (spirochetes or spirilla).
• Reproduction is asexually through binary fission or sexually by conjugation. The process of circulation and digestion is carried out through diffusion.
• The Monera kingdom includes all bacteria that may infect animals, humans and plants. But most of the members are termed as beneficial bacteria, rather than pathogenic bacteria. You can read in detail about pathogenic bacteria list.
• The Monerans kill organisms causing pathogenic diseases, break down algae and can even recycle chemical pollutants like hydrogen sulfide and ammonia. You can read more on beneficial bacteria to humans.
• Bacteria that grow in the root nodules help break down atmospheric nitrogen into fixed nitrogen,
• The bacteria that forms the natural flora of the intestines are very important for proper digestion.
• One of the many Monera characteristics also includes production of antibiotics likes streptomycin that is useful for treatment of infections
• Monorans can be identified by their characteristic of cell wall that can be or not stained by Gram staining.
• Most of the Monorans can survive harsh environment by producing spore coat.
Kingdom Monera Division
The kingdom Monera is divided into many sub kingdoms as well as phyla. These sub kingdoms and phyla include:
• Sub-kingdom Archaebacteria: The Monera characteristics includes survival in harsh conditions intolerable to other organisms.
• Sub-Kingdom Eubacteria: This kingdom includes all bacteria known as 'true bacteria' except arhaebacteria.
• Phylum Anaerobic Phototrophic Bacteria: Monera characteristics that include photosynthesis that does not use water as the initial substrate and does not produce oxygen as end product.
• Phylum Cyanobacteria: These monereans are blue-green bacteria that carry out photosynthesis with help of chlorophyll A and blue pigment phycocynin.
• Phylum Prochlorophyta: These are organisms that contain chlorophyll A and B.
• Phylum Schizophyta: These Monera include heterotrophic eubacteria that include different types of bacteria like saprobes and parasites.
The kingdom Monera contains organisms with the simplest structures as compared to other kingdoms. They are the first life form to have evolved on planet earth. I hope this article on Monera characteristics has helped you understand the organisms belonging to this animal kingdom classification better.