How will an organism lacking a membrane-bound nucleus be classified?

An organism lacking a membrane-bound nucleus will be classified as a prokaryote because prokaryotic cells are characterized by the absence of a defined nucleus and other membrane-bound organelles. Instead, their genetic material, which is typically a single circular DNA molecule, is located in a region called the nucleoid. This structural feature distinguishes prokaryotes from eukaryotes, which do have a membrane-bound nucleus and complex cellular structures.

Organisms such as bacteria and archaea fall under the category of prokaryotes, and they play essential roles in various ecosystems. In contrast, eukaryotic organisms, like plants, animals, and fungi, all possess nuclei and are more complex in terms of cell structure and function.