Name a key feature that distinguishes prokaryotic cells from eukaryotic cells.

Prokaryotic cells are characterized by the absence of a nucleus, which is a fundamental distinction from eukaryotic cells. Instead of being contained within a membrane-bound nucleus, the genetic material in prokaryotic cells is located in a region called the nucleoid. This difference is significant as it reflects the overall complexity of cellular organization; prokaryotes tend to be simpler and smaller in structure compared to eukaryotes, which possess a defined nucleus and various organelles like mitochondria and endoplasmic reticulum that compartmentalize cellular functions. This absence of a nucleus in prokaryotes is a key feature that has implications for their evolutionary history and their ability to reproduce swiftly through binary fission.