Kingdom Archaebacteria

Description-Members of the kingdom Archaebacteria are small, simplistic microorganisms. They are certainly prokaryotic, lacking a complex intracellular structure, but despite this many are able to survive in the most hostile locations on the planet, and are not reliant on any one source energy. Some archaebacteria sustain themselves by consuming hydrogen gas or metal ions, where other organisms could not. Still other archaebacteria live inside more complex organisms and act as mutualists or commensals.

Body Plan-Archaebacteria are unicellular.

Divergent Event-The lineage of archaebacteria may be the most ancient one in earth’s history, given that they are the simplest of prokaryotes. Due to their incredibly long evolutionary line, experts find it difficult to identify exactly when they appeared and differentiated from their relatives, Eubacteria, but examination of fossils seems to suggest that it occurred about 3 billion years ago, which is the age of the oldest sediment in which archaebacteria have been found.

Metabolism-Archaebacteria are both heterotrophic and autotrophic. An example autotrophic archaebacteria are members of the class Halobacteria, which absorb light by use of the pigment rhodopsin, and an example of heterotrophic archaebacteria are members of the class Methanobacteria, which metabolize methane gas to create energy.

Digestion-Digestion within Archaebacteria is intracellular: Archaebacteria engulf their nutrients and digest them within their cell membranes

Circulation-Archaebacteria possess no circulatory system

Respiration-Archaebacteria possess no respiratory system

Nervous System-Archaebacteria possess no nervous system

Reproduction-Archaebacterial reproduction is asexual reproduction. Most Archaebacteria perform binary division to reproduce, splitting their nuclei into two.

Examples: Ferroglobus placidus, which lives next to hydrothermal vents off the coast of Italy, able to endure temperatures of up to 95 degrees Celcius

Sulfolobus solfataricus, an archaebacterium found in Yellowstone National Park, which thrives in areas that have volcanic activity and acidic pH levels.