Why is mitochondrial DNA often useful in disaster victim identification?

Why is mitochondrial DNA often useful in disaster victim identification?

• A. It mutates faster than nuclear DNA, providing more markers.
• B. High copy number in cells makes mtDNA recoverable from degraded remains; mtDNA provides maternal lineage information.
• C. It resides on a separate chromosome that is rarely shared between individuals.
• D. It is inherited from both parents like autosomal DNA.

Answer: (B)

The main idea is why mitochondrial DNA is particularly useful when remains are damaged. Each cell contains many mitochondria, and each mitochondrion has multiple copies of mtDNA. That high copy number means mtDNA is more likely to be recovered from degraded material and can be amplified even when nuclear DNA is sparse or fragmented. In addition, mtDNA is inherited only from the mother and does not recombine, so individuals along the same maternal line share the same mtDNA haplotype. This lets investigators link remains to maternal relatives and establish identity when nuclear DNA isn’t available or is inconclusive. While mtDNA is less individualized than nuclear DNA, its resilience in degraded samples makes it especially valuable in disaster victim identification.

The main idea is why mitochondrial DNA is particularly useful when remains are damaged. Each cell contains many mitochondria, and each mitochondrion has multiple copies of mtDNA. That high copy number means mtDNA is more likely to be recovered from degraded material and can be amplified even when nuclear DNA is sparse or fragmented. In addition, mtDNA is inherited only from the mother and does not recombine, so individuals along the same maternal line share the same mtDNA haplotype. This lets investigators link remains to maternal relatives and establish identity when nuclear DNA isn’t available or is inconclusive. While mtDNA is less individualized than nuclear DNA, its resilience in degraded samples makes it especially valuable in disaster victim identification.