Reproduction
Further information: Asexual reproductionArchaea reproduce asexually by binary or multiple fission, fragmentation, or budding; meiosis does not occur, so if a species of archaea exists in more than one form, all have the same genetic material. Cell division is controlled in a cell cycle; after the cell's chromosome is replicated and the two daughter chromosomes separate, the cell divides. Details have only been investigated in the genus Sulfolobus, but that cycle has characteristics that are similar to both bacterial and eukaryotic systems. The chromosomes replicate from multiple starting-points (origins of replication) using DNA polymerases that resemble the equivalent eukaryotic enzymes. However, the proteins that direct cell division, such as the protein FtsZ, which forms a contracting ring around the cell, and the components of the septum that is constructed across the center of the cell, are similar to their bacterial equivalents.
Both bacteria and eukaryotes, but not archaea, make spores. Some species of Haloarchaea undergo phenotypic switching and grow as several different cell types, including thick-walled structures that are resistant to osmotic shock and allow the archaea to survive in water at low salt concentrations, but these are not reproductive structures and may instead help them reach new habitats.
Read more about this topic: Archaea
Famous quotes containing the word reproduction:
“Were I called on to define, very briefly, the term Art, I should call it the reproduction of what the Senses perceive in Nature through the veil of the soul. The mere imitation, however accurate, of what is in Nature, entitles no man to the sacred name of Artist.”
—Edgar Allan Poe (18091845)
“It is so characteristic, that just when the mechanics of reproduction are so vastly improved, there are fewer and fewer people who know how the music should be played.”
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“Although Samuel had a depraved imaginationperhaps even because of thislove, for him, was less a matter of the senses than of the intellect. It was, above all, admiration and appetite for beauty; he considered reproduction a flaw of love, and pregnancy a form of insanity. He wrote on one occasion: Angels are hermaphrodite and sterile.”
—Charles Baudelaire (18211867)