Mitochondrial DNA can be taken from bone, hair, or teeth and used in DNA typing. What are the benefits to using mitochondrial DNA over nuclear DNA? mtDNA requires a much smaller sample than nuclear DNA. mtDNA is useful if the nuclear DNA is degraded. mtDNA is inherited from the mother and father's egg cells, unlike nuclear DNA. mtDNA is present in all maternal relatives of the person being investigated.

The answer is; mtDNA is useful if the nuclear DNA is degraded.

There is a higher likelihood of salvaging intact mtDNA compared to nuclear DNA in degraded cells such as old bones and teeth. The reason for this is that there are numerous mitochondria in cells compared to one nucleus. Therefore the mtDNA will provide substantial samples compared to nuclear DNA in such cases.

Answer: mtDNA is present in all maternal relatives of the person being investigated.

Explanation:

Mitochondria are the organelles found in all eukaryotes and are considered as the powerhouse of the cell.

Mitochondrial DNA (MtDNA) is the genetic system of the mitochondria. Unlike other cell organelles mitochondria and chloroplast have their own genomes. The inheritance of the mitochondrial DNA is different from the inheritance of the nuclear DNA. The mitochondrial DNA is passed down from the mother to their daughters unchanged, this is because no recombination takes place in this DNA.

Since, the mitochondrial DNA is only passed by the mother it is said to have uniparental inheritance. It is not passed down by the father as the sperm does not contain mitochondria.

Thus, the uniparental inheritance of the mitochondrial DNA provides a way to trace the maternal ancestry of an individual.