Which statement about mitochondrial DNA inheritance is correct?

• A. It is inherited from both parents
• B. It is located in the nucleus
• C. It is inherited maternally
• D. It is identical in all individuals

Answer: (C)

Mitochondrial DNA inheritance is maternal because the mitochondria that populate the zygote come from the mother’s egg, and paternal mitochondria are typically not transmitted or are actively degraded after fertilization. This means offspring inherit their mtDNA from their mother, not from their father, which is why mtDNA can trace maternal lineages across generations. The genetic material in question resides in the mitochondria themselves, not in the nucleus, so it follows a separate inheritance pattern from nuclear DNA. It is not identical in all individuals; there are sequence differences that define different maternal lineages, and occasional heteroplasmy can cause variation between tissues within the same person. In forensic contexts, this maternal inheritance and relatively stable transmission make mtDNA useful for identifying maternal relationships or analyzing degraded samples where nuclear DNA is limited.