Salient Features Of Kingdom Monera

All prokaryotes, or unicellular creatures without nuclear membranes, belong to the Kingdom Monera. Eubacteria and archaebacteria are two phylogenetically separate families within this biological kingdom. Eubacteria and archaebacteria are genetical as distinct as eukaryotes (organisms with nuclear membranes, such as protists, plants, animals (invertebrates and vertebrates), and fungi).

Archaebacteria and eubacteria differ morphologically in a few significant ways. While both groups contain cell walls, their cell membranes, as well as their overall chemical makeups, are chemically distinct. Most archaebacteria thrive in highly adverse settings, such as excessively salty seas or hot sulphur springs, even though there is no clear and fast differentiation between the functions that the two types of bacteria play. Some eubacteria dwell in these hostile settings as well, but others live in places as diverse as surface soils and termite digestive tracks.

Bacteria, despite their modest size (most bacteria are far smaller than eukaryotic cells), play a crucial part in the natural world. Bacteria are the most common cause of illnesses ranging from strep throat to bubonic plague. However, only a small percentage of microorganisms cause illness. The majority of them are useful to other creatures.

Some bacteria are photoautotrophs, meaning they feed on both inorganic and organic matter. Certain photoautotrophs have the ecologically significant capacity to fix nitrogen from the atmosphere and make it accessible to plant roots in some instances. Saprophytes are bacteria that break down decaying organic matter. Others dwell in symbiotic relationships with other creatures’ digestive tracts, assisting in the digestion of a wide range of dietary components.

In comparison to eukaryotes, Monerans have a comparatively basic structure and reproductive cycle. They don’t have nuclei or complicated organelles. Internal membranes are used to house specialised components such as photosynthetic apparatus. Moneran genetic material is likewise rather straightforward. Instead of the complex chromosomes present in eukaryotes, they contain tiny bacterial chromosomes and plasmids. The majority of Monerans reproduce by binary fission.

Monera’s classification:

Archaebacteria, Eubacteria, and Cyanobacteria are the three sub-kingdoms of the Monera kingdom.

Archaebacteria: 

Archaebacteria are a sort of single-cell creature that is so unlike other current life forms that they have caused scientists to rethink how they define life. Archaebacteria contain a few traits that aren’t found in other “modern” cell types. These are some of them:

1. The chemistry of the cell membrane is unique.

ether-linked phospholipids are used in the cell membranes of archaebacteria, while ester-linked phospholipids are used in the cell membranes of bacteria and eukaryotes.

2. unique Gene transcription.

Although archaebacteria have a single, spherical chromosome like bacteria, their gene transcription is comparable to that of eukaryotic cells’ nuclei.

As a result, most genes involved in most life processes, such as cell membrane formation, are more closely shared by Eukarya and Bacteria, whereas genes involved in the process of gene transcription are more closely shared by Eukarya and Archaea.

3. Methanogenesis, a kind of anaerobic respiration that creates methane, is only possible in archaebacteria.

Eubacteria

Eubacteria are prokaryotic microorganisms that consist of a single cell with no nucleus and a single circular chromosome carrying DNA. Eubacteria can be gram-negative or gram-positive, and they are important in the economy, agriculture, and medicine. Lactobacilli is an example.

After the copying of genetic material, Eubacteria reproduce by splitting the parent cell into two daughter cells, a process known as binary fission. In adverse conditions such as nutritional shortage, chemical exposure, or radiation, certain bacteria can generate spores. Although these spores are unable to replicate, they are extremely resistant to poisons, radiation, heat, and dryness. Bacillus and Clostridium, which produce spores, are considered dangerous bacteria, hence sterilising treatments must eradicate bacterial spores. When environmental circumstances improve, bacterial spores begin to vegetate and proliferate once more.

Eubacteria are prokaryotic cells with only one cell. A circular chromosome is seen in them. Furthermore, the cell wall of eubacteria is made up of peptidoglycan. Their morphology and physiology are vastly different.

Cyanobacteria:

Cyanobacteria are both aquatic and photosynthetic, meaning they can live in water and produce their food. They are normally unicellular and tiny since they are bacteria, yet they do develop in colonies large enough to view. They hold the distinction of being the world’s oldest fossils, dating back more than 3.5 billion years! It may surprise you to learn that cyanobacteria are still alive and well; they are one of the world’s largest and most significant bacterial groupings.

Cyanobacteria are the key sources of nitrogen fertiliser for rice and bean growth. Cyanobacteria have also had a significant role in determining the trajectory of evolution and ecological change over the length of Earth’s history. During the archaean and proterozoic Eras, many cyanobacteria produced the oxygen atmosphere that humans rely on today. The atmosphere had radically different chemistry before that period, making it unsuited for life as we know it today.

The genesis of plants is another significant contribution of cyanobacteria. The chloroplast, which plants use to create food, is a cyanobacterium that lives inside the plant’s cells. Cyanobacteria began to take up residence within specific eukaryote cells sometime in the late Proterozoic or early Cambrian, producing nourishment for the eukaryote host in exchange for a home. Endosymbiosis is the process that leads to the formation of the eukaryotic mitochondrion.

Cyanobacteria are sometimes referred to as “blue-green algae” since they are photosynthetic and watery. This word is useful for describing creatures in the water that produce their food, but it has no bearing on the connection between cyanobacteria and other species known as algae. Cyanobacteria are bacteria’s cousins, not eukaryotes, and cyanobacteria are exclusively connected to the chloroplast in eukaryotic algae.

Conclusion:

Monerans are extremely beneficial creatures. They are very useful for soil. Also, they contribute to the nitrogen cycle. They’re also used in the manufacture of various foods and medications. Methanogens play a great role in the treatment process of sewage. Archaebacteria serve as a source of food too for many organisms.