Prokaryotes vs. Eukaryote Cells
Prokaryotic cells
Prokaryotes are the most ancient forms of life on Earth, including true bacteria and the archaebacteria (now called archaea)
These cells lack organelles, but they have circular DNA
Size: Very small; 0.1 – 10 μm, or 10x smaller than eukaryotic cells
Diversity: Unknown number of species; maybe a few thousand to a million
Major groups (see below for groups covered in BOT III: Plant Diversity)
Prokaryotic Groups
Eukaryotic cells
Eukaryotes appeared around 2 billion years ago, as simple algae
These cells have membrane-bound organelles present, including a nucleus
Size: Small, but not nearly as small as prokaryotes; 10 – 100 μm long
Diversity: 7 – 10 million species
Major groups (see below for groups covered in BOT III: Plant Diversity)
Eukaryotic Groups
Archaeplastida: plants, red algae, and green algae
Chromalveolates: water molds, diatoms, brown algae and dinoflagellates
Excavates: Euglena, Giardia
Unikonts: fungi, animals, slime molds
What about viruses?
Viruses don't have cells, but learn more about them here