life forms in the world. It is important to examine the biology of chonanoflagellates and how it occurs in nature.
Choanoflagellates
Choanoflagellates are colorless flagellates which are 5-10 micron and have a well-defined collar. They may be individual or live in colonies and “may live free in the water, or attached to substrates such as the spines of the Chaetoceros affinis (thalassa.gso.uri.edu/rines/ecology/choanofl.htm).”
Choanoflagellates are made up of only about 150 species and are not “a diverse group of protists. They are small single-celled protests, found in both fresh waters and the oceans, taking their name (“collar-flagellate”) from the circle of closely packed microvilli, or slender fingerlike projections, that surrounds the single flagellum by which choanoflagellates both move and take in food (www.ucmp.berkeley.edu/protista/choanos.html).” The funnel-shaped collar is contractible and strains out the bacteria which the choanoflagellate feeds on (www.mhhe.com/biosci/genbio/biolink/student/olc2/chap31outline.htm).
Protists belong to the “kingdom Protoctista, a new classification in most modern taxonomic systems (http://education.yahoo.com/reference/dictionary/entries/60/p0616000.html).” Choanoflagellates are closely related to “both the fungi and the animals (www.nearctica.com/nathist/protista/prointro.htm).” They are the ancestors of the sponges, “and of all the protoctists, it the choanoflagellates that are the most likely ancestors of animals (web.lander.edu/rsfox/112protc.html).”
Conclusion
Choanoflagellates are protists and are related to both fungi and animals. These single-cell organisms are believed to be early ancestors to sponges and animals.
Works Cited
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< halassa.gso.uri.edu/rines/ecology/choanofl.htm>).
(Introduction to the Choanoflagellates. (accessed 10 November, 2003).
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(Protists. (accessed 10 November, 2003).
< http://education.yahoo.com/reference/dictionary/entries/60/p0616000.html>).
(Protists. (accessed 10 November, 2003).
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(Protists. (accessed 10 November, 2003).
(Survey of Organismal Diversity. (accessed 10 November, 2003).
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