Mitochondria gene (True statement)a) Paternal transmissionb) Maternal transmissionc) Mendelian inheritanced) Mitochondrial myopathy

**Core Concept**
Mitochondrial DNA (mtDNA) is responsible for encoding some of the genes necessary for the production of proteins involved in the electron transport chain. Unlike nuclear DNA, mtDNA is inherited solely from the mother, as only egg cells contribute mitochondria to the fertilized egg.

**Why the Correct Answer is Right**
The correct answer is related to the mechanism of inheritance of mitochondrial DNA. Mitochondrial DNA is a circular, double-stranded molecule found in the mitochondria of eukaryotic cells. Since only egg cells contribute mitochondria to the fertilized egg, all the mitochondria in a person's cells are inherited from their mother. This unique mode of inheritance is due to the fact that during fertilization, the sperm's mitochondria are typically excluded from the fertilized egg, leaving only the egg's mitochondria to be inherited.

**Why Each Wrong Option is Incorrect**
* **Option A:** Mitochondrial DNA is not inherited from the father, as the sperm's mitochondria are typically excluded from the fertilized egg.
* **Option B:** While mitochondrial DNA is indeed transmitted from the mother, this option is incomplete and does not fully capture the mechanism of inheritance.
* **Option C:** Mitochondrial DNA does not follow Mendelian inheritance patterns, as it is not subject to the same rules of segregation and independent assortment as nuclear DNA.
* **Option D:** Mitochondrial myopathy is a disease resulting from mutations in mitochondrial DNA, but it is not a statement about the inheritance of mitochondrial DNA.

**Clinical Pearl / High-Yield Fact**
Mitochondrial diseases, such as mitochondrial myopathy, can be caused by mutations in mitochondrial DNA that affect the production of essential proteins involved in energy production.

**Correct Answer:** B. Maternal transmission