Forensic Science DNA Profiling Study Guide

Forensic Science – DNA Profiling Study Guide

1. What does DNA stand for? 2. DNA contains the instructions for cells to make ______. 3. What is the shape of the DNA molecule? 4. What makes up the rungs of the DNA ladder? 5. What are the 4 nitrogen bases in DNA? 6. How many chromosomes do human body cells contain? 7. Which type of DNA is found in the nucleus? 8. Which type of DNA is found in the mitochondria? 9. Which type is passed to the offspring by only the mother? 10. What is a gene? 11. What is the name of the project designed to map the gene locations/sequence of bases on all 23 pairs of human chromosomes? 12. How many base pairs are found in human DNA? 13. Define exon. 14. Define intron. 15. Which of the two (exon or intron) is NOT involved in protein making? 16. Which of the two makes up the majority of our DNA? 17. In which of the two would you expect to find the most mutations? 18. Define polymorphism. 19. Name the two types of polymorphisms used in DNA profiling. (whole word…not just the abbreviations). 20. Who discovered and developed the technique that is used in DNA profiling? 21. Which are longer in length…VNTRs or STRs? 22. Describe the relationship between a child’s DNA profile and his/her parents’ profiles…include “DNA bands” in your answer. 23. What is the source of DNA in blood? 24. How could it be possible to obtain DNA from feces? From semen? From sweat? 25. What must be present in a hair sample in order to extract DNA? 26. What is the name of the reaction that generates multiple copies of original DNA evidence? When might this reaction be used? 27. Give 3 examples of ways that DNA evidence might become contaminated. 28. Be familiar with the 8 precautions that should be taken when handling DNA evidence. 29. What are the 4 steps of DNA fingerprinting? 30. During which step is the DNA isolated from the evidence sample? 31. During which step is the DNA cut into fragments? 32. How does a restriction enzyme work? 33. Which step of the fingerprinting process produces multiple copies of a DNA fragment? 34. Which step of the fingerprinting process involves fragments of DNA moving through a gel layer? 35. During electrophoresis, which DNA fragments move faster? 36. During electrophoresis, do the DNA fragments move toward the positively charged end or the negatively charged end? 37. If the left side of a gel layer has a negative charge, and the right side of the gel layer has a positive charge; which DNA fragments would you expect to be closer to the right side of the gel…the larger or smaller fragments? 38. Describe the 4 steps of electrophoresis. 39. How are DNA fragments visualized in electrophoresis? 40. What are the two types of probes described in our notes? 41. Which type of probe produces an image on X-ray film? 42. How many probes should be used to ensure accuracy in DNA fingerprinting? 43. What does CODIS stand for? 44. What is CODIS? 45. Why would an individual’s DNA profile be in CODIS? 46. List 6 uses of DNA fingerprinting.