What best defines prokaryotes?

• A. Unicellular microbes that lack a true nucleus.
• B. Multicellular organisms with a defined nucleus.
• C. Organisms with membrane-bound organelles.
• D. Eukaryotic cells with complex compartments.

Answer: (A)

Prokaryotes are the simplest cellular life forms defined by the lack of a true nucleus. Their DNA isn’t enclosed within a membrane-bound nucleus; instead, it resides in a nucleoid region inside a single, usually small cell. They also lack membrane-bound organelles, which is a hallmark distinguishing them from eukaryotes. Because of this combination, prokaryotes are typically unicellular microbes, such as bacteria and archaea, whereas organisms with a defined nucleus and internal compartments are eukaryotes. So describing prokaryotes as unicellular microbes that lack a true nucleus best captures what sets them apart.