A prokaryotic cell differs from a eukaryotic cell primarily in that a prokaryotic cell lacks a nucleus and membrane-bound organelles, whereas a eukaryotic cell has a well-defined nucleus and membrane-bound organelles. Prokaryotic cells are generally smaller and simpler, and their DNA is located in a nucleoid region within the cytoplasm, not enclosed by a membrane. Eukaryotic cells, on the other hand, have their DNA enclosed within a nucleus and possess complex organelles such as mitochondria, the endoplasmic reticulum, and the Golgi apparatus. Additionally, prokaryotes are mostly unicellular organisms like bacteria and archaea, while eukaryotes can be unicellular or multicellular, including animals, plants, fungi, and protists.

Key Differences

• Nucleus : Absent in prokaryotes; present in eukaryotes with a membrane-bound nucleus.
• Organelles : Prokaryotes lack membrane-bound organelles; eukaryotes have them.
• Cell Size : Prokaryotes are smaller (0.1–5 µm); eukaryotes are larger (10–100 µm).
• DNA Organization : Prokaryotic DNA is usually a single circular chromosome in the nucleoid; eukaryotic DNA is linear and enclosed in the nucleus.
• Cell Type : Prokaryotes are unicellular; eukaryotes are mostly multicellular (some unicellular).
• Examples : Prokaryotes include bacteria and archaea; eukaryotes include animals, plants, fungi, and protists.

These structural differences also correspond to differences in complexity and functionality of the cells.