Which statement best describes non-nuclear DNA?

• A. DNA located outside the nucleus
• B. DNA found only in mitochondria
• C. DNA located within the nucleus
• D. DNA that codes for proteins

Answer: (A)

Non-nuclear DNA is genetic material found outside the nucleus. In many cells, most DNA sits in the nucleus, but organelles such as mitochondria (and chloroplasts in plants) carry their own small genomes separate from the nuclear DNA. This means non-nuclear DNA is DNA located outside the nucleus. The other ideas mix up location with function or are too narrow: DNA that’s only in mitochondria ignores other non-nuclear DNA; DNA located in the nucleus is the opposite; and DNA that codes for proteins describes function, not where the DNA is located.