They are found in the soil, the air, the water, and in or on every organism on the face of the earth, including humans. Prokaryotes also inhabit extreme environments such as salt flats, hot springs, and also thermal vents located deep within the earth. Prokaryotic cells are microscopic in size, averaging in size from 1 to 10 micrometers in length. These cells lack membrane- enclosed internal structures. This means that they do not have a nucleus or cytoplasmic organelles such as mitochondria or chloroplasts.
Prokaryotes have rigid cell walls formed from protein like chains and sugars.
In prokaryotic cells, mitosis does not occur. Mitosis is the replication of the chromosomes and the production of two nuclei in one cell. Prokaryotes move by means of long, hair like structures called flagella. Eukaryotic cells are considerably more complicated. These are the cells of plants, animals, and other familiar organisms.