How are mitochondria inherited in humans?

• A. They are randomly inherited from either parent.
• B. They are inherited exclusively from the mother.
• C. They are inherited equally from both parents.
• D. They are inherited exclusively from the father.

Answer: (B)

Verified step by step guidance

1. Understand the concept of mitochondrial inheritance: Mitochondria are organelles responsible for energy production in cells, and they contain their own DNA (mtDNA). Unlike nuclear DNA, which is inherited from both parents, mitochondrial DNA is inherited differently.
2. Learn about the mechanism of mitochondrial inheritance: In humans, mitochondria are inherited exclusively from the mother. This is because the egg cell contributes the majority of the cytoplasm, including mitochondria, to the zygote during fertilization, while the sperm cell contributes primarily nuclear DNA.
3. Explore why paternal mitochondria are not inherited: During fertilization, the mitochondria from the sperm are typically destroyed or excluded, ensuring that only maternal mitochondria are passed on to the offspring.
4. Recognize the implications of maternal inheritance: This unique inheritance pattern means that mitochondrial DNA can be used to trace maternal lineage and study evolutionary relationships.
5. Review the correct answer: Based on the biological mechanism of mitochondrial inheritance, mitochondria are inherited exclusively from the mother.