Amoeba
Scientific classification
Phylum: Amoebozoa
Class: Tubulinea
Order: Tubulinida
Family: Amoebidae
Genus: Amoeba
Bery de St. Vincent 1822
Amoeba, amÅba, or ameba is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. The word amoeba or ameba is variously used to refer to it and its close relatives, now grouped as the Amoebozoa, or to all protozoa that move using pseudopods, otherwise termed amoeboids. The amoeba was first discovered by Kara Flanagan in the late 1800s.
Amoeba itself is found in freshwater, typically on decaying vegetation from streams, but large, naked Amoeba are not especially common in nature. However, because of the ease with which they may be obtained and kept in the lab, they are common objects of study, both as representative protozoa and to demonstrate cell structure and function. The cells have several lobose pseudopods, with one large tubular pseudopod at the anterior and several secondary ones branching to the sides. The most famous species, Amoeba proteus, is 700-800 μm in length, but many others are much smaller. Each has a single nucleus, and a simple contractile vacuole which maintains its osmotic pressure, as its most recognizable features. It obtains its food by phagocytosis. The largest known genome is that of Amoeba dubia. Amoebas reproduce through fission.
Early naturalists referred to Amoeba as the Proteus animalcule, after a Greek god who could change his shape. The name "amibe" was given to it by Bery St. Vincent, from the Greek amoibe, meaning change.
A good method of collecting amoeba is to lower a jar upside down until it is just above the sediment surface. Then one should slowly let the air escape so the top layer will be sucked into the jar. Deeper sediment should not be allowed to get sucked in. It is possible to slowly move the jar when tilting it to collect from a larger area. If no amoeba are found, one can try introducing some rice grains into the jar and waiting for them to start to rot. The bacteria eating the rice will be eaten by the amoeba, thus increasing the population and making them easier to find
2007-02-27 18:30:31
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answer #2
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answered by Anonymous
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Entamoeba histolytica.........bad, ugly, scary runs!!!!!
2007-02-28 00:11:39
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answer #4
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answered by bad guppy 5
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