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''Polychaos dubium'' is a freshwater amoeboid and one of the larger species of protist. Like other amoebozoans, ''P. dubium'' moves by means of temporary projections called pseudopods. ''P. dubium'' reportedly has one of the largest genomes of any organism known. ''Polychaos dubium'' was previously known as ''Amoeba dubia''.〔 The author who named the species later recognized it as different from species of ''Amoeba'', and so designated it the type species of the genus ''Polychaos''.〔 Unlike species of ''Amoeba'', ''P. dubium'' lacks longitudinal ridges on its pseudopods.〔 〕 == Physical characteristics == A few characteristics distinguish ''Polychaos dubium'' from other species of ''Polychaos''. The crystals floating in its cytoplasm take the shape of flat bipyramids, flat plates, or clustered platelets. The nucleus is ellipsoid in shape, has granules next to the membrane, and lacks an endosome. The cell is usually polypodal (has many pseudopodia), and the endoplasm and ectoplasm of the cytoplasm are clear.〔 During rapid locomotion, ''P. dubium'' may become monopodial (present only one pseudopod), 〔 (【引用サイトリンク】 work = micro *scope - version 6.0 ) 〕 but there are an average of 12 pseudopodia. 〔 (【引用サイトリンク】 work = Protist Information Server ) 〕 ''Polychaos dubium'' has one of the largest genomes known for any organism, consisting of 670 billion base pairs of DNA,〔 〕 which is over 200 times larger than the human genome. The authors of one study, however, suggest treating that measurement with caution, because it was taken before the advent of modern genomic methods.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Polychaos dubium」の詳細全文を読む スポンサード リンク
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