Mitochondrial inheritance Practice Questions
19 free Mitochondrial inheritance practice questions for the USMLE Step 1, each with the correct answer and a detailed explanation. Open any question below, or take the full set as an interactive quiz.
Questions
19 questions
All Mitochondrial inheritance questions
- Q1. Which inheritance pattern best describes transmission of mutations in mitochondrial DNA (mtDNA) in humans?
- Q2. In a family pedigree for a mitochondrial disease, which of the following patterns is expected if the disease is due to an mtDNA mutation?
- Q3. What is “heteroplasmy” in the context of mitochondrial genetics?
- Q4. Which phenomenon explains why siblings of the same mother may have different severity of a mitochondrial disorder despite inheriting the same mutation?
- Q5. Which structural feature of human mtDNA distinguishes it from nuclear DNA?
- Q6. Why do mitochondrial diseases often affect tissues with high energy demand (like brain and muscle)?
- Q7. Which of the following statements about recombination in human mitochondrial DNA is most accurate?
- Q8. Which of the following is a possible mechanism by which paternal mitochondria are excluded from inheritance in humans?
- Q9. If a woman carries a homoplasmic harmful mtDNA mutation, what is the risk that her child (regardless of sex) will inherit the mutation?
- Q10. Which of the following scenarios would argue against a strictly maternal mtDNA inheritance model in humans?
- Q11. Which term describes a condition in which some cells in a person’s body have mutated mtDNA and others have normal mtDNA, leading to variable expression of a mi…
- Q12. Which of the following features is NOT typical of mitochondrial (mtDNA) inheritance of disease?
- Q13. Why does mitochondrial inheritance behave as a single locus rather than following Mendelian segregation rules?
- Q14. Which principle explains why rare deleterious mtDNA mutations may be lost in one generation despite being present in the mother?
- Q15. Which of the following is a potential challenge when diagnosing mitochondrial diseases using family history alone?
- Q16. Which of the following statements about nuclear-encoded mitochondrial proteins and their inheritance is correct?
- Q17. Which mitochondrial feature makes mtDNA a useful tool for tracing human maternal ancestry over many generations?
- Q18. Which of the following would be strong evidence for a nuclear (rather than mitochondrial) cause of a suspected mitochondrial disease?
- Q19. Why might a heteroplasmic mother have both affected and unaffected children when carrying a deleterious mtDNA mutation?