Most prokaryotes are small, single-celled organisms that have a relatively simple structure. Prokaryotic cells are surrounded by a plasma membrane, but they have no internal membrane-bound ...

Planctomycetes challenge our concept of the bacterial cell and of a prokaryote as a cell structure type, as well as our ideas about origins of the eukaryote nucleus. Planctomycetes Are Important ...

Eukaryotic cell DNA in a nucleus, plasmids are found in a few simple eukaryotic organisms. Prokaryotic cell DNA is a single molecule, found free in the cytoplasm; additional DNA is found on one or ...

Scientists propose that the eukaryotic branch of this family tree formed when two prokaryotes, an ancient bacterium and archaeal cell, merged, forming a symbiotic relationship maintained over time. 1 ...