2. Archaebacteria
Archaebacteria are known to be the
oldest living organisms on earth. They
belong to the kingdom Monera and are
classified as bacteria because they
resemble bacteria when observed under
a microscope. Apart from this, they are
completely distinct from prokaryotes.
However, they share slightly common
characteristics with the eukaryotes.
3. Characteristics of
archaebacteria
•Archaebacteria are obligate or facultative anaerobes, they
flourish in the absence of oxygen and that is why only they
can undergo methanogenesis.
•The rigid cell wall provides shape and support to the
archaebacteria. It also protects the cell from bursting under
hypotonic conditions.
•The mode of reproduction is asexual, known as binary
fission.
•Achaebacteria are indifferent towards major antibiotics.
4. • The difference in their ribosomal RNA suggest that they diverged
from both prokaryotes and eukaryotes.
• They can survive in acidic and alkaline aquatic regions, and also in
temperature above boiling point.
• They can withstand a very high pressure of more than 200
atmospheres.
• These do not possess membrane-bound organelles such as nuclei,
endoplamic reticulum, mitochondria, lysomes or chloroplast.
• The cell membranes of the Archaebacteria are composed of lipids.
• The size of Archaebacteria ranges from one-tenth of a micrometer to
more than 15 micrometer. Some of archaebacterial have flagella.
7. crenarchaeota
The Crenarchaeota are Archea, which exist in an
broad range of habitats. They have special
protiens that help them to function at
temperature as high as 230 degrees Celcuis. They
can be found in deep-sea vents and hot spring,
regions with superheated water. These include
thermophles, hyperthermophiles,
8. euryarchaeota
These can survive under extremely alkaline
conditions and have the ability to produce
methane, unlike any other living being on
earth.
9. korarchaeota
They possess the genes common with
Crenarchaeota and Euryarchaeota. These are
supposed to be the oldest surviving
organism on earth.
13. lokiarcheota
It is a thermophilic archaebacterium found in deep-sea
vents kwon as the Lokims castle. Some of the genes of
the genome are involved in phagocytosis. It is believed
thet Lokiarcheota and Eukaryotes shared a common
ancestor several billion years ago.
14. Methanobrevibacter
smithii
It is an methane-producing bacteria found in the
human gut. It helps in the breakdown of complex
plant sugars and extracts energy from the food
consumed by us.
Editor's Notes
2. It also protects the cell from bursting under hypotonic condition
4. Because they contain plamios which have antibiotics resistance enzymes
