Pyroccocus furiosus archaea Archaea are single-celled organisms that are similar to bacteria but have been found to have higher organism characteristics. This was discovered when sampling the DNA of bacteria. A new domain of Archaea was set up because of the differences found. The thin strands or filaments are flagella. Each organism has a group of flagella at one end of the cell that is used for locomotion. P. furiosus is a hyperthermophile and it is only found in very hot water. At temperatures below 70 degrees Celsius it will freeze and die. It is found in hot water vents under the sea that are subject to great pressure and oxygen depletion. This archaea uses sulfur for respiration instead of oxygen.

The members of this kingdom are prokaryotes ( single-celled organisms that have no pre-defined nucleus or membrane-bound organelles). Most prokaryotes are microscopic. Their collective biological mass (biomass) is at least ten times that of all eukaryotes (Eukaryote is an organism whose cells contain complex structures enclosed within membranes) . The number of prokaryotes in a single handful of fertile soil is greater than the number of people who have ever lived. What has enabled these tiny organisms to dominate the biosphere throughout their history? One reason for their success is a wealth of adaptations that enable various prokaryotes to inhabit diverse environments. Prokaryotes thrive almost everywhere, including places too acidic, too salty, too cold, or too hot for most other organisms.

The Monerans are too simple in their structure and, therefore, their morphological characters are of less value for classifying them. Their classification, therefore, uses functional characteristics, i.e., biochemical, physiological and ecological. All Monerans, or all bacteria, are prokaryotes. The bacteria are most simple and smallest of all cellular organisms (0.5 to 50μ), and may be studied under the high power of light microscope.

Thus , if we put together Monera is a kingdom of prokaryotes which includes organisms such as bacteria, cyanobacteria, mycoplasma etc. They are present almost everywhere. They have little difference in outer shape and form. These are unicellular organisms which have no specific mode of nutrition. They can be aerobic or anaerobic.

Cell wall is present and is made of peptidoglycan with mucin covering. They have naked DNA. No membrane bound organelles are present. Endoplasmic reticulum, mitochondria are absent. They multiply by binary fission. The kingdom monera has been divided into two groups which are: Archaebacteria – the ancient type and Eubacteria – the true type. The true type is further divided into bacteria and cyanobacteria.