Final answer:
The mitochondrial genome is characterized by the absence of introns in its compact and efficient structure, with mtDNA being particularly useful for tracing evolutionary relationships and genealogy due to its rapid mutation rate and maternal inheritance pattern.
Step-by-step explanation:
The characteristic of the mitochondrial genome that is correct among the options provided is D) There are no introns present. Unlike the majority of nuclear genes, the mitochondrial genome is compact, and most of its genes lack introns. Mitochondrial DNA (mtDNA) mutates at a much more rapid rate compared to nuclear DNA, and this property makes it a valuable tool for studying evolutionary relationships and genealogy. Additionally, mtDNA is unique because it is maternally inherited, and replication of the DNA does not occur in the nucleus but within the mitochondria themselves. The DNA in mitochondria also differs from nuclear DNA as it is not bound to histones.