Question

why isnt mitochondrial dna a unique identifier?
multiple choice
mitochondrial dna is inherited through the maternal lineage. all female offspring inherit their mothers mitochondria, and therefore the same mitochondrial dna. as a result, all female family members that share a maternal lineage would have the same mitochondrial dna. mitochondrial dna can therefore be used to confirm or eliminate a persons relationship within a maternal line, but cannot be used to identify a specific individual.
mitochondrial dna is inherited through the paternal lineage. all offspring inherit their fathers mitochondria, and therefore the same mitochondrial dna. as a result, all family members that share a paternal lineage would have the same mitochondrial dna. mitochondrial dna can therefore be used to confirm or eliminate a persons relationship within a paternal line, but cannot be used to identify a specific individual.
mitochondrial dna is inherited through the maternal lineage. all offspring inherit their mothers mitochondria, and therefore the same mitochondrial dna. as a result, all family members that share a maternal lineage would have the same mitochondrial dna. mitochondrial dna can therefore be used to confirm or eliminate a persons relationship within a maternal line, but cannot be used to identify a specific individual.

Explanation:

Mitochondrial DNA (mtDNA) is maternally inherited—all offspring (not just female) inherit their mother’s mtDNA. This means all members of a maternal lineage share identical mtDNA, so it cannot uniquely identify an individual. The correct option states this maternal inheritance and universal offspring inheritance from the mother.

Answer:

The third option: Mitochondrial DNA is inherited through the maternal lineage. All offspring inherit their mother's mitochondria, and therefore the same mitochondrial DNA. As a result, all family members that share a maternal lineage would have the same mitochondrial DNA. Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a maternal line, but cannot be used to identify a specific individual.