What Are the Main Differences Between Prokaryotes and Eukaryotes?

The main difference between prokaryotic and eukaryotic cells is that eukayrotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells lack these structures. Prokaryotic cells are the simplest of all living things, and they only exist as unicellular bacteria. All multicellular organisms and higher-order bacteria are comprised of eukaryotic cells.

Prokaryotes and eukaryotes also differ in terms of cell size. According to the University of Maryland, prokaryotic cells are typically about 0.2 to 2.0 micrometers in diameter, while eukaryotic cells are between 10 and 100 micrometers in diameter. Although both types of cells may have flagella, the structure of these flagella is different. Those of prokaryotic cells consist of two protein building blocks, while those of eukaryotic cells are comprised of complex arrangements of microtubules.

While prokaryotic cells do not contain membrane-bound organelles, they do contain ribosomes. However, these are smaller than the ribosomes found in eukaryotic cells. The DNA of prokaryotic cells is also circular rather than linear, as it is in eukaryotes. The two types of cells also divide in different manners: prokaryotic cells by binary fission and eukaryotic cells by mitosis. Sexual reproduction in prokaryotes involves only the transfer of DNA fragments between two cells, while sexual reproduction in eukaryotic cells occurs by the process of meiosis.