What type of DNA is inherited only from the mother to the daughter?

Mitochondrial DNA is inherited solely from the mother because it is contained within the mitochondria, which are passed down through the maternal lineage during fertilization. The sperm contributes nuclear DNA but does not typically provide mitochondria to the zygote, meaning the maternal line is the sole source of mitochondrial DNA for offspring. This characteristic is particularly useful in studies of maternal ancestry, as it allows researchers to trace lineage and understand evolutionary relationships among populations.

Nuclear DNA, Y-chromosomal DNA, and chromosomal DNA all have different modes of inheritance. Nuclear DNA is inherited from both parents, Y-chromosomal DNA is passed from father to son, and chromosomal DNA encompasses both maternal and paternal contributions. These differences underscore the unique inheritance pattern of mitochondrial DNA, emphasizing its maternal-only transmission.