Plants, animals, fungi, slime moulds, protozoa, and algae all comprise eukaryotic cells. These cells are about fifteen times wider than a typical prokaryote and can be as much as a thousand times greater in volume.
The main distinguishing feature of eukaryotes as compared to prokaryotes is compartmentalisation:
- the presence of membrane-bound compartments in which specific metabolic activities take place.
- Most important among these is a cell nucleus, a membrane-delineated compartment that houses the eukaryotic cell's DNA.
This nucleus gives the eukaryote its name, which means "true nucleus." Other differences include:
- The cell(plasma) membrane resembles that of prokaryotes in function, with minor differences in the setup. Cell walls may or may not be present.
- The eukaryotic DNA is organized in one or more linear molecules, called chromosomes, which are associated with histone proteins.
- All chromosomal DNA is stored in the cell nucleus, separated from the cytoplasm by a membrane.
- Some eukaryotic organelles such as mitochondria also contain some DNA.
- Many eukaryotic cells are ciliated with primary cilia.
- Primary cilia play important roles in chemosensation, mechanosensation, and thermosensation.
- Cilia may thus be "viewed as a sensory cellular antennae that coordinates a large number of cellular signaling pathways, sometimes coupling the signaling to ciliary motility or alternatively to cell division and differentiation."
- Eukaryotes can move using motile cilia or flagella. Eukaryotic flagella are less complex than those of prokaryotes.