What is the main difference between prokaryotic and eukaryotic cells?

The main difference between prokaryotic and eukaryotic cells lies in the presence of a nucleus. Prokaryotic cells, which include bacteria and archaea, do not have a true nucleus. Instead, their genetic material is located in a region called the nucleoid, which is not membrane-bound. In contrast, eukaryotic cells, which make up organisms such as plants, animals, fungi, and protists, contain a well-defined nucleus enclosed by a nuclear membrane that houses their DNA.

The presence of a nucleus not only differentiates these two types of cells but also signifies a higher level of complexity in eukaryotic cells, allowing for more intricate regulation of gene expression and cellular processes. This structural organization plays a crucial role in the functioning and life cycles of eukaryotic organisms.