How is mitochondrial DNA primarily inherited?

Mitochondrial DNA (mtDNA) is inherited exclusively from the mother. This mode of inheritance occurs because the mitochondria in the sperm are typically destroyed after fertilization, leaving only the mitochondria from the egg to contribute to the genetic makeup of the offspring. As a result, all of an individual's mitochondrial DNA can be traced back to their maternal lineage. This unique aspect of mitochondrial inheritance makes it a valuable tool in genetic studies related to maternal ancestry and evolutionary biology. In contrast, the other forms of inheritance listed are incorrect; paternal inheritance does not play a role in mitochondrial DNA transmission, and siblings share a genetic combination from both parents but do not contribute to the inheritance of mtDNA in the way described.