DIPLOID MITOSIS VS CLONAL INHERITANCE. “Unlike the diploid genome in the nucleus which undergoes Mendelian segregation during mitosis, the mitochondrial genome is maternally inherited and therefore can be considered to be clonal in nature. The cell has multiple mitochondria, each containing multiple mtDNA copies, which undergo replicative segregation into two daughter cells.”
http://onlinelibrary.wiley.com/doi/10.1002/1873-3468.12061/full