All complex life forms on Earth, including plants and animals, are made up of eukaryotic cells; they are more sophisticated than bacterial or archaeal cells, which are prokaryotic. Eukaryotes have ...

Prokaryotic single-celled organisms, the ancestors of modern-day bacteria and archaea, are the most ancient form of life on our planet, first appearing roughly 3.5 billion years ago. The first ...

Prokaryotes are ancient, simple forms of life that include bacteria and archaea. These cellular life forms lack membrane-bound organelles. Those organelles, which include the nucleus and the ...

John M. Archibald is in the Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada, and also at the Institute for Comparative Genomics, Dalhousie ...