Characters controlled by the DNA of extranuclear organelles are not inherited according to Mendelian laws and are transmitted only through the female line, since only the female gametes have an appreciable amount of cytoplasm.

• 由于细胞质大多来自母体所产生的配子，所以由细胞核外的细胞器的DNA所控制的遗传性状一般只随母系而遗传，也不符合孟德尔定律。