Where is genetic material located in a prokaryotic cell?

• A. Nucleus enclosed by a nuclear envelope.
• B. In the cytoplasm but within a membrane-bound organelle.
• C. Mitochondria house the genetic material.
• D. Nucleoid region, not enclosed by a nucleus.

Answer: (D)

Prokaryotic cells do not have a nucleus. Their genetic material sits in the nucleoid region inside the cytoplasm, not enclosed by a membrane. This region holds the main chromosome (and sometimes small circular DNA pieces called plasmids) without a surrounding nuclear envelope. Because there is no nucleus, DNA isn’t separated into a distinct, membrane-bound compartment.

The other scenarios would require a membrane-bound nucleus or organelles, which prokaryotes lack. A nucleus enclosed by a nuclear envelope is a feature of eukaryotic cells. A membrane-bound organelle enclosing DNA would place DNA inside a compartment that prokaryotes don’t have. Mitochondria contain DNA in eukaryotic cells, but prokaryotes do not have mitochondria. So the genetic material in a prokaryotic cell is located in the nucleoid region, not enclosed by a nucleus.