Archaea, single celled microorganisms with circular plasmoidal genome are one of the three domains of life.Several similarities exist between archaea with both prokaryotes and eukaryotes; its been observed that archaea and bacteria have no internal cell membranes and both contain a cytoplasm, cell membrane and cell wall, however differ chemically such as certain tRNA functions of archaea differ from bacteria and are more similar with eukaryotes. Compounds such as Peptidoglycan, chitin and cellulose, present in bacteria, fungi and plants respectively are however absent in the cell walls of Archaea. Furthermore, archaea and eukaryotes are not sensative to certain chemical inhibitants in the rybosomes, whereas bacteria is.


Many Archaea live in the most extreme conditions in earth such as high temperatures, acids and bases; in fact some species of it requre temperatures of up to 80 degrees celsius inorder to breed. These conditions are similar to that of the conditions found in earth over 3.5 billion years ago, which suggest that archaea are closely related to the original forms of life. These characteraristics have great importance to scientific research since Archaea produce 'extremozymes' allowing them to survive such extreme conditions.

http://www.ucmp.berkeley.edu/archaea/archaeamm.html
http://www.bookrags.com/research/archaea-gen-01/
http://www.ias.ac.in/resonance/Mar1998/pdf/Mar1998p32-40.pdf