Eukaryotes and prokaryotes

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.

Three different cells - a plant cell, a bacteria cell and an animal cell

Comparing cell types

Eukaryotic cellProkaryotic cell
SizeMost are 5 μm – 100 μmMost are 0.2 μm – 2.0 μm
Outer layers of cellCell membrane - surrounded by cell wall in plants and fungiCell membrane - surrounded by cell wall
Cell contentsCytoplasm, cell organelles include mitochondria, chloroplasts in plants and ribosomesCytoplasm, ribosomes, no mitochondria or chloroplasts
Genetic materialDNA in a nucleus - plasmids are found in a few simple eukaryotic organismsDNA is a single molecule, found free in the cytoplasm - additional DNA is found on one or more rings called plasmids
Type of cell divisionMitosisBinary fission

A group of organisms called Archaea are also prokaryotic.