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. What is the difference in an exon and an intron in DNA?
14. Which of the two (exon or intron) is NOT involved in protein making?
15. Which of the two (exon or intron) makes up the majority of our DNA?
16. Define polymorphism.
17. Name the two types of polymorphisms used in DNA profiling. (whole word…not just the
abbreviations).
18. Who discovered and developed the technique that is used in DNA profiling?
19. How many base pairs in length are…. VNTRs? STRs?
20. Describe the relationship between a child’s DNA profile and his/her parents’ profiles…include “DNA
bands” in your answer.
21. What is the source of DNA in blood?
22. Name all of the possible biological sources of DNA.
23. What must be present in a hair sample in order to extract DNA?
24. What is the name of the reaction that generates multiple copies of original DNA evidence? When might
this reaction be used?
25. Give 3 examples of ways that DNA evidence might become contaminated.
26. What are the 4 steps of DNA fingerprinting?
27. During which step is the DNA isolated from the evidence sample?
28. During which step is the DNA cut into fragments?
29. How does a restriction enzyme work?
30. What is another name for restriction enzymes?
31. Which step of the fingerprinting process produces multiple copies of a DNA fragment?
32. Which step of the fingerprinting process involves fragments of DNA moving through a gel layer?
33. During electrophoresis, which size DNA fragments move faster and travel farther?
34. During electrophoresis, do the DNA fragments move toward the positively charged end or the
negatively charged end?
35. 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?
36. Describe the 4 steps of electrophoresis.
37. What tool is used to visualize DNA fragments in electrophoresis?
38. What are the two types of probes described in our notes?
39. Which type of probe produces an image on X-ray film?
40. How many probes should be used to ensure accuracy in DNA fingerprinting?
41. What is CODIS and what does CODIS stand for?
42. What are the reasons an individual’s DNA profile would be in CODIS?
43. List 6 uses of DNA fingerprinting.