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 ...

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.

Bacteria are amongst the simplest of organisms - they are made of single cells. Their cell structure is simpler than the cells of animals, plants and fungi. Size Most are 5 μm - 100 μm.