In the previous post, all prokaryotes are classified under Monera. However, it was found that prokaryotes are more diversed than expected. Hence, the 3 domains systems was created to further classify the prokaryotes and eukaryotes. In general, prokaryotes are divided into 2 domains. Bacteria (eubacteria) and archaea respectively. All eukaryotes are put into the 3rd domain. Archaea is further divided into 3 main groups, methanogens, Thermoacidophiles and extreme halophiles.
prokaryotes:A unicellular organism having cells lacking membrane-bound nuclei; bacteria are the prime example but also included are blue-green algae and actinomycetes and mycoplasma.
Monera: Prokaryotic bacteria and blue-green algae and various primitive pathogens; because of lack of consensus on how to divide the organisms into phyla informal names are used for the major divisions.
eukaryotes: An organism with cells characteristic of all life forms except primitive microorganisms such as bacteria; i.e. an organism with 'good' or membrane-bound nuclei in its cells.
eubacteria: A large group of bacteria having rigid cell walls; motile types have flagella.
archaea: are a group of single-celled microorganisms.
methanogens: Archaebacteria found in anaerobic environments such as animal intestinal tracts or sediments or sewage and capable of producing methane; a source of natural gas.
Thermoacidophiles: is an extreme archaebacteria which thrives in acidous, sulfur rich, high temperature environments.
halophiles: Archaebacteria requiring a salt-rich environment for growth and survival.
references: definations from wordweb, www.biologie.uni-hamburg.de for image, information from notes.
No comments:
Post a Comment