Which feature is characteristic of eukaryotic organisms?

The presence of a distinct nucleus is a defining characteristic of eukaryotic organisms. In eukaryotes, the genetic material is enclosed within a membrane-bound nucleus, allowing for a more regulated and organized approach to gene expression and replication. This structure distinguishes eukaryotes from prokaryotic organisms, which lack a nucleus and have their genetic material dispersed within the cytoplasm.

Eukaryotic organisms also tend to be larger and more complex than prokaryotic organisms, which makes the option regarding size incorrect. While many eukaryotic cells can be observed using a light microscope, this feature is not unique to them, as prokaryotic cells can also sometimes be seen this way. Therefore, the presence of a distinct nucleus is the most accurate feature that highlights the differences between eukaryotic and prokaryotic life forms.