Eukarya/eukaryotes multicellular

Eukarya is a group of organisms with a membrane-bound nucleus. They are multicellular and diverse in species machinery. Some eukaryotes have sexual reproduction, and gene exchange can occur also by transduction and transformation. Genetic information is based on several complex RNA polymerases, and translation starts with methionine. Eukarya was long considered as the third major domain of the life tree. Current molecular results... 

Higher organisms were believed to be unable to withstand extreme environments most probably because of their cellular complexity and compartmentalization. Therefore research on extremophiles has focused mainly on organisms belonging to the Archaea and Bacteria kingdoms. However, a significant number of eukaryotes, both unicellular and multicellular, have evolved to live and thrive in extreme environments (e.g. Alvinella pompejana, Tetrahymena thermophila and Dunaliella salina). Hence, extremophiles span all three domains of life Archaea, Bacteria and Eukarya [61]. 

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