Maternal inheritance is a form of inheritance in which the DNA is transferred due to the cytoplasm of the egg cell. In this way, the characteristics or traits in the offspring are originated from the mother because the extranuclear DNA that was present in the egg was expressed during the process of fertilization. This extranuclear DNA is typically referred to as the mitochondrial DNA. It is much smaller in size when compared to nuclear DNA and is pivotal in the process of cellular metabolism.
These mitochondria are located in the cytoplasm of the egg cell and get transferred from the mother to the offspring. The sperms have also got these mitochondria but they do not get incorporated into the zygote. During the division of cells, these mitochondria are distributed randomly among the daughter cells.