A circular molecule of DNA surrounded by a membrane is characteristic of which type of organism?

A circular molecule of DNA surrounded by a membrane is characteristic of bacteria. In bacteria, the genetic material is typically organized in a circular form, which is distinct from the linear chromosomes found in eukaryotic organisms, such as animals, plants, and fungi. The presence of a membrane surrounding the DNA is indicative of prokaryotic cells, which lack a true nucleus. This structure allows for more efficient replication and expression of genes in bacterial cells. Additionally, some bacteria may contain plasmids as well, which are small circular DNA molecules that can carry additional genetic information.