The division between prokaryotes and eukaryotes reflects the existence of two very different levels of cellular organization; only eukaryotic cells have an enveloped nucleus that contains its chromosomal DNA, and other characteristic membrane-bound organelles including mitochondria.

Cell size. Typical prokaryotic cells range from 0.1 to 5.0 micrometers (μm) in diameter and are significantly smaller than eukaryotic cells, which usually have diameters ranging from 10 to 100 μm. The figure below shows the sizes of prokaryotic, bacterial, and eukaryotic, plant and animal, cells as well as other molecules and organisms on a.

Eukaryotes have an enclosed nucleus, while prokaryote lack membrane-bound organelles. Prokaryotic and eukaryotic cells are the basic units of life on Earth. The basic distinction between prokaryotes and eukaryotes is that prokaryotes lack a membrane-bound nucleus and organelles.

Bacteria and Archaea are both prokaryotes but differ enough to be placed in separate domains. An ancestor of modern Archaea is believed to have given rise to Eukarya, the third domain of life. Major groups of Archaea and Bacteria are shown. Characteristics of bacterial phyla are described in Figure 22.12 and Figure 22.13.

What is the difference between Prokaryotic and Eukaryotic cells? The defining characteristic.

Prokaryotic cells are simple cells that do not have a true nucleus or other cell organelles. Bacteria and Archaea are the two domains of life that are prokaryotes. Prokaryotes can be contrasted with eukaryotes, which have more complex eukaryotic cells with a nucleus and organelles.