What distinguishes prokaryotic cells from eukaryotic cells?

Prokaryotic cells are distinguished from eukaryotic cells primarily by the absence of membrane-bound organelles and a nucleus. In prokaryotic cells, the genetic material is not enclosed within a nuclear membrane; instead, it exists as free DNA located in the cytoplasm, often organized in a single circular chromosome.

In contrast, eukaryotic cells contain membrane-bound organelles, such as the nucleus, mitochondria, and endoplasmic reticulum, which compartmentalize various cellular functions. The presence of these structures is a hallmark of eukaryotic cells, allowing for more complex cellular activities and organization.

Because prokaryotic cells have free DNA rather than a nucleus and do not possess the various organelles seen in eukaryotic cells, the correct answer encapsulates all these distinguishing features, highlighting that all the stated characteristics set prokaryotes apart from eukaryotes.