How is mitochondrial dna (mtdna) vyping used in forensic science?
an unknown mtdna sample is matched to a sample of nuclear dna that was found at a crime scene.
an unknown mtdna sample is matched to a sample of mtdna that was found at a crime scene,
an unknown nuclear dna sample is matched to a sample of nuclear dna that was found at a crime scene,
an unknown nuclear dna sample is matched to a sample of mtdna that was found at a crime scene,

The correct answer is second-An unknown mtDNA sample is matched to a sample of mtDNA that was found at a crime scene.

Explanation:

Mitochondrial DNA is different from the nuclear DNA because mitochondrial DNA is inherited from mother only but nuclear DNA is inherited from mother and father both.

The mitochondrial DNA can be easily obtained from samples and contains two hypervariable regions which have unique sequence in each individual.  

Therefore in mitochondrial typing, these variable sequence of an unknown mitochondrial DNA is matched with the sample of mtDNA that was found at a crime scene. The matching confirms the presence of that individual at the crime scene.  

Therefore, the correct answer is-An unknown mtDNA sample is matched to a sample of mtDNA that was found at a crime scene.

idk what happened..you tell