Final answer:
Prokaryotes, specifically bacteria, have a distinct cell structure that lacks a nucleus, have DNA that exists as a single circular "loop," and contain plasmids. The DNA is located in the nucleoid region of the cell.
Step-by-step explanation:
Prokaryotes, specifically bacteria, are characterized by certain features such as not having a nucleus, having DNA that exists as a single circular "loop," and lacking membrane-bound organelles. The DNA is located in a region of the cell called the nucleoid. Bacterial chromosomes are covalently closed circles and are not organized around histone proteins like eukaryotic chromosomes. Prokaryotes also often have plasmids, which are shorter circular DNA molecules that can carry specific genes.