Final answer:
The assertion that mitochondrial DNA makes up a significant percentage of a person's genes is false. Mitochondrial DNA, consisting of approximately 37 genes, is a small part of our genetic material and is inherited exclusively from the mother, used to trace maternal lineage.
Step-by-step explanation:
The statement saying that mitochondrial DNA makes up a significant percentage of a person's genes in the body is false. Mitochondrial DNA is indeed a crucial part of our genetic makeup, but it represents a very small fraction of the total genes. Each human cell contains about 23 pairs of chromosomes that are derived from both parents, which include thousands of genes. Moreover, each cell has mitochondria, typically around 1700, and each mitochondrion may have multiple copies of the mtDNA genome, which includes about 37 genes.
Exclusively inherited from the mother, mitochondrial DNA is used in tracing maternal ancestry and studying evolutionary relationships because it mutates rapidly and does not undergo recombination. Unlike the nuclear DNA, where we inherit half from our father and half from our mother, mtDNA is only inherited maternally. The mitochondrial genomics, while fascinating and useful in tracking genealogy, does not contribute significantly to the overall count of an individual's genes.