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 the egg.
2. A child inherits mitochondrial diseases entirely from mother and not from father.

Which of the statements given above is/are correct?

The correct option is Both 1 and 2.

Let us analyze each of the given statements in detail:

Statement 1: Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of the egg.
This statement is correct. Mitochondrial Replacement Therapy (MRT) involves replacing defective mitochondria in a mother's egg or embryo with healthy mitochondria from a donor. This technique can be performed using Maternal Spindle Transfer (MST), where nuclear DNA is transferred before fertilization, or Pronuclear Transfer (PNT), where nuclear DNA is transferred after in vitro fertilization (IVF) of the egg. Both methods effectively prevent maternal transmission of mitochondrial diseases to the offspring.

Statement 2: A child inherits mitochondrial diseases entirely from mother and not from father.
This statement is correct. Mitochondria contain their own distinct circular DNA (mtDNA). During fertilization, the sperm contributes only nuclear DNA, as the mitochondria located in the sperm's tail are destroyed or excluded during zygote formation. Thus, virtually all functional mitochondria in the developing embryo originate exclusively from the cytoplasm of the egg cell provided by the mother. Consequently, mitochondrial traits and diseases follow maternal inheritance.

Since both Statement 1 and Statement 2 are scientifically correct, the correct answer is Both 1 and 2.