What describes a prokaryote?

A prokaryote is best described as a unicellular organism without a true nucleus, which aligns with the characteristics of prokaryotic cells. These organisms, which include bacteria and archaea, do not have a membrane-bound nucleus; instead, their genetic material is located in a region called the nucleoid. This absence of a true nucleus is a key distinction that separates prokaryotes from eukaryotes, which do have organized nuclei.

Additionally, prokaryotic cells are generally smaller and simpler in structure compared to eukaryotic cells. The lack of membrane-bound organelles further emphasizes their simplicity. While many prokaryotes can replicate through binary fission, a method of asexual reproduction, this characteristic alone doesn't encompass the defining cellular structure of prokaryotes, making the second choice the most descriptive of what a prokaryote is.