Methanogens

The word Archaea comes from the Ancient Greek word meaning ancient things. the first observed archaea were living in harsh environments such as hot springs and salt lakes. Archaea are found in almost every habitat, including soils, oceans, and marshlands. They are found in the gut, mouth, and skin. these are old bacteria. These are the organisms when the first life originated. these are the first organisms as they are capable of surviving in extreme conditions e,g in hot conditions at almost 100 degrees, highly acidic conditions i.e. high PH and high salt areas.
Archaebacteria Characteristics
Archaebacteria have several characteristics
1. the Archaebacteria are primitive from an evolutionary point of view
2. they are considered the oldest living fossils
3. the Archaebacteria are prokaryotic organisms
4. Archaebacteria have cell membranes made up of branched lipids and hydrocarbons.
5. their cell wall is made up of complex polysaccharides and complex polypeptides.
6. the nucleoid is present
7. Peptidoglycan is absent in the cell wall of Archaebacteria.
8. Mostly behave as obligate anaerobes i.e oxygen is a poison to these bacteria.