Final answer:
The choice of a mitochondrial gene for gene barcoding on its higher mutation rate, which aids in distinguishing closely related species through DNA sequencing.
Step-by-step explanation:
The choice of using a mitochondrial gene for barcoding of genes depends on the gene's higher mutation rate. Genes most useful for barcoding eukaryotes with the exception of plants are mitochondrial genes. The ability to catalog an organism using rapid DNA sequencing methods is important for assessing biodiversity, phylogenetics, and conservation efforts. Mitochondrial DNA (mtDNA) is advantageous because its higher mutation rate compared to nuclear DNA provides the fine-scale resolution necessary for distinguishing closely related species. Additionally, mtDNA is generally more abundant in cells, which simplifies the process of DNA extraction and sequencing.
It is important to note that mitochondrial genes are not the best choice for all organisms; for instance, in plants, chloroplast genes are often used for barcoding due to certain limitations of mtDNA in those organisms.