1. B. Urea 2. B. Diabetes (Friday Special) 3. B. 100% or E. 50% 4. D. Two recessive color blindness alleles on the X chromosomes 5. D. Crossing over of the SRY gene (Friday Special) 6. A. True 7. B. Atrioventricular valves 8. D. LDL's 9. C. 1 in 2 10. E. Releasing hormones 11. E. Anterior pituitary 12. C. Water conservation 13. A. Acetylcholine 14. D. Variable environments 15. A. The production of germ cells with half the number of chromosomes found in the parental cells 16. C. Hypothalamus 17. C. The placebo effect (Friday Special) 18. B. Intermediate relatedness (third cousins) resulted in the highest reproductive success 19. A. Pheromone 20. B. The coefficient of inbreeding 21. A. Kidney stones 22. B. Recessive alleles 23. E. Dopamine 24. C. Surfactant (Friday Special) 25. A. Prostaglandins 26. E. Endorphins 27. B. Water (Friday Special) 28. B. Nitric oxide (NO) 29. B. Tuberous sclerosis 30. A. Pleiotropy 31. D. Malaria 32. C. Carbon dioxide levels in the blood rise to high levels 33. B. A multiple allele system 34. C. Reduced exposure to sunlight by small children (Friday Special) 35. C. Inbreeding depression 36. B. Oligodendrocytes (Friday Special) 37. C. Modifier genes affect the expression of the tongue-rolling allele 38. A. Release drugs 39. D. Homogametic 40. C. Angioplasty 41. C. Activation of genes 42. C. Females are ornamented, males are choosy, and males carry eggs in a brood pouch until hatching 43. B. Melatonin 44. E. Creating faceless avatars of actual male dancers which females then rated 45. D. Ectothermic homeotherms 46. A. Formaldehyde 47. A. Serotonin 48. E. Antiseptic environments that alter the immune system (Friday Special) 49. B. Ammonia 50. C. Helicobacter pylori