Discussion Questions: How DNA Evidence Works
DNA fingerprinting is only the first step in proving a suspect's DNA matches crime scene DNA. What is the second, and why is it important? What does non-coding DNA mean? Why is it important to create DNA profiles that include VNTRs from both maternal and paternal chromosomes in a chromosome pair? Why do you think DNA profiles produce discrete bands on a gel, instead of long solid streaks? [Hint: Think about what makes an individual band travel down the gel during electrophoresis.] Examine the DNA "ladders" on the gels. What do you think they are, and why do you think they are there? What can DNA profiles be used for, besides proving guilt or innocence in a courtroom?
