The unicellular organism Thiomargarita namibiensis has a diameter of 700 μm and is surrounded by a cell wall. In T. namibiensis, the genetic material lies freely in the cytoplasm, where it is present as thousands of copies of circular DNA. A large vacuole occupies most of the cell and contains vital chemicals needed for metabolism. Which statement is correct?
- AIt must be a eukaryote because a diameter of 700 μm is too large for a prokaryote.
- BIt must be a plant because it contains a vacuole.
- CIt must be a plant because it is enclosed in a cell wall.
- DIt must be a prokaryote because its DNA is circular and located in the cytoplasm.