Final answer:
Prokaryotic plasmids are small circular double-stranded DNA molecules that exist in the cytosol and can be transferred between bacteria, often conferring traits such as antibiotic resistance.
Step-by-step explanation:
The general structural features of a prokaryotic plasmid are that it is a small circular, independent double-stranded DNA molecule. Plasmids exist in the cytosol of prokaryotic cells, not in a nucleus, because prokaryotic cells lack membrane-bound organelles, including a nucleus. These plasmids can often be transmitted from one bacterium to another, carrying with them genes that can be beneficial, such as those providing antibiotic resistance.
Unlike eukaryotic chromosomes, prokaryotic DNA and plasmids are not organized around histone proteins. The DNA of prokaryotes is found in the nucleoid region of the cytoplasm. In addition to their single circular chromosome, prokaryotes may have these plasmids, which are not essential for normal growth but can confer advantageous traits to the bacterium.