Final answer:
The presence of a membrane-enclosed nucleus is a characteristic of eukaryotic cells. Prokaryotic cells, such as bacteria and archaea, do not have a membrane-enclosed nucleus.
Step-by-step explanation:
The presence of a membrane-enclosed nucleus is a characteristic of eukaryotic cells. Unlike prokaryotic cells, such as bacteria and archaea, eukaryotic cells contain a nucleus that houses their DNA and is surrounded by a nuclear membrane. This feature distinguishes them from prokaryotic cells, which have a single piece of circular DNA in the nucleoid area of the cell and do not possess a nucleus. Viruses are also not classified under this characteristic since they are not considered living cells and do not have a membrane-enclosed nucleus.
The presence of a membrane-enclosed nucleus is a characteristic of eukaryotic cells. Eukaryotic cells are found in organisms such as plants, animals, fungi, and protists. They are characterized by having a nucleus that houses the genetic material, which is enclosed by a membrane called the nuclear membrane.
Prokaryotic cells, on the other hand, do not have a membrane-enclosed nucleus. Examples of prokaryotes include bacteria and archaea. These cells have their genetic material floating freely in the cytoplasm.