How is Mitochondrial DNA Inherited in Humans

Question

How is mitochondrial DNA inherited in humans?
A) All mitochondrial DNA is inherited from the mother.
B) Fifty percent of mitochondrial DNA is inherited from the mother and 50 percent from the father.
C) All mitochondrial DNA is inherited from the father.
D) Only 75 percent of mitochondrial DNA is inherited from the father; the other 25 percent is inherited from the mother.

Accepted Answer

Mitochondrial DNA is only inherited from the mother in humans. This is because during fertilization, the egg contributes most of the cytoplasm, including mitochondria, to the developing embryo. Sperm, on the other hand, typically contribute very little cytoplasm, and the mitochondria present in the sperm are usually degraded shortly after fertilization. Therefore, all of the mitochondrial DNA in an individual's cells is inherited from their mother.