In addition to the nucleus, eukaryotic cells may contain several other types of organelles, which may include mitochondria, chloroplasts, the endoplasmic reticulum, the Golgi apparatus, and lysosomes.

Planctomycetes challenge our concept of the bacterial cell and of a prokaryote as a cell structure ... may have originated (Poole & Penny 2007). One of these involves fusion between cells from ...

Prokaryotic cell DNA is a single molecule, found free in the cytoplasm; additional DNA is found on one or more rings called plasmids.