[Campbell Biology P.485] Which of the following statements best describes the advantage of u... | Practice Question
Which of the following statements best describes the advantage of using short tandem repeats STRs for forensic DNA profiling compared to earlier methods like blood or tissue typing?
A: STR profiling requires a much larger sample size, making it less practical for minute quantities of evidence found at crime scenes.
B: Earlier blood or tissue typing methods can definitively identify an individual, whereas STR profiling can only exclude suspects.
C: STR profiling analyzes highly polymorphic regions with variable repeat numbers across individuals, providing a unique genetic profile that can identify an individual with high certainty.
D: Earlier methods like blood typing can detect specific cell-surface proteins, offering higher accuracy and reliability than DNA-based methods.
Explanation
The text clearly states that DNA testing, specifically using STRs, can identify individuals with a high degree of certainty because the DNA sequence of every person is unique except identical twins . STRs exploit highly variable regions of DNA, making them ideal for creating a unique genetic profile, and they require much smaller samples than older methods.