Final answer:
The person expected to have different mtDNA from the rest of the family is Your dad (D), as mtDNA is inherited maternally and he would have received it from his own mother, not from the maternal line of the person giving the gift. The correct answer is option D. Your dad
Step-by-step explanation:
If you gifted your entire family with at-home DNA test kits for Christmas and are interested in genealogy, particularly in mitochondrial DNA (mtDNA), you would expect to have different mtDNA from the rest of the family members in anyone who is not matrilineally related. In this case, the person with different mtDNA from the rest of the family members would be Your dad (D).
mtDNA is passed down strictly through the maternal line, from mothers to their children without recombination, making it an excellent tool for tracing maternal ancestry. Every person inherits mtDNA from their mother, so siblings will typically share the same mtDNA unless there is a mutation. However, your father would have received his mtDNA from his own mother, not from your maternal line.
This is consistent with the molecular anthropology research tracing back to an ancestor commonly referred to as "Mitochondrial Eve" based on analysis of mtDNA patterns. Researchers utilize the mutations in mtDNA to map evolution and genealogical relationships, providing insight into our matrilineal ancestry.