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