In the context of hereditary diseases, consider the following statements : 1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg. 2. A child inherits mitochondrial diseases entirely from mother and not from father. Which of the statements given above is/are correct?

1. Statement 1 is correct. Mitochondrial replacement therapy (MRT), also known as three-person IVF, involves transferring the nuclear genetic material from an egg or zygote with faulty mitochondria into an enucleated donor egg or zygote with healthy mitochondria. This procedure can indeed be performed either before fertilization (using techniques like Maternal Spindle Transfer) or after in vitro fertilization (IVF) of the egg (using techniques like Pronuclear Transfer). The aim is to prevent the transmission of mitochondrial diseases from parent (specifically the mother) to child. 2. Statement 2 is correct. Mitochondria, the organelles responsible for energy production, contain their own DNA (mtDNA). During fertilization, the sperm contributes primarily nuclear DNA, while the egg contributes both nuclear DNA and the cytoplasm, which contains the mitochondria. Therefore, a child inherits mitochondria and any associated mitochondrial diseases almost entirely from the mother through the egg cytoplasm, not from the father. Therefore, both statements are correct.