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Cellular and Molecular Biology

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High Mutation Rate in Mitochondrial DNA

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In animals, mitochondrial DNA (mtDNA) has been observed to evolve more quickly than most genes carried on chromosomes in the nucleus. It may be because mutation rates of mtDNA are generally higher than those of nuclear chromosomal DNA.

Though there are​ some controversy and ongoing research into the subject, which of the following mechanisms has been most suggested to be the cause of the higher mtDNA mutation rate?

A

mtDNA is replicated by a more error-prone DNA polymerase.

B

Mitochondria have few or no DNA repair mechanisms.

C

There is a greater incidence of oxidative damage to mtDNA.

D

mtDNA is less protected from ionizing radiation than is nuclear DNA.