1. A. Acetabulum of the femur 2. B. Mitochondrial DNA 3. C. Electrons 4. B. More persistent than testosterone 5. C. Peer review 6. E. Calcium 7. D. Products 8. E. Myoglobin 9. E. Arrival of human immigrants in Australia 10. C. Myostatin 11. B. Low levels of Carbon-13 (Friday special) 12. A. Producing ATP, high-energy compounds (NADPH), and oxygen 13. A. Electrons 14. A. Sciatica 15. C. Potassium 40/Argon 40 16. A. Shin splints 17. A. Blood clot formation 18. B. A natural resistance to obesity 19. D. Carbon-hydrogen bonds 20. E. Calcium 21. C. Creatine phosphate 22. C. Ribosomes 23. A. Gout 24. C. Cholesterol 25. C. Oxygen 26. E. Theory 27. D. Social darwinism (Friday special) 28. B. Rigor mortis 29. A. Relatively high (Friday special) 30. D. Cosmic rays 31. C. Neutrons (Friday special) 32. D. The Yucatan Peninsula (Friday special) 33. B. Osteoporosis 34. E. All of the above may apply, depending on the circumstances 35. B. 50,000 36. D. Dysfunction of the autoimmune system 37. A. C4 metabolism (Friday special) 38. A. Wendell Johnson Stuttering Project 39. D. Glycogen 40. C. Low endurance 41. D. Hydrophobic interactions 42. A. Nervous 43. B. Queen Victoria (Friday special) 44. C. Hydrogen 45. D. Intelligent design 46. D. Sarcoplasmic reticulum 47. D. An enzyme 48. C. Haversian canals 49. D. 4 50. A. Archaea