40. DNA fingerprinting is used in many situations to help identify individuals. Analyze the situation below before answering the questions that follow.
A man was attacked and robbed, but remembers nothing of the incident because he fell and hit his head. He has numerous cuts and abrasions from the event, and blood was found under his fingernails. A piece of torn clothing with a bloodstain on it was also found at the scene.
Two people were seen near the crime scene. Both males, they say they don't know each other and just happened to be near the scene at the time of the attack. One of the males has a fresh scratch across his face, while the other male has a scratch on his right arm.
It's not clear from observations of the crime scene how many individuals were involved in the crime. Two males have reportedly been robbing individuals in the vicinity. There's a rumor that the two are brothers.
a. Explain two DISTINCT uses that DNA fingerprinting could be used for in this situation. In particular, what are two important issues that should be resolved to help clarify the identity of the individuals of the body fluids found at the scene?
My answer: Each individual, other than identical twins, has a unique DNA fingerprint. The banding patterns for the 2 men could be compared to establish whether they are brothers. Also, because it can be performed on a sample of DNA found in blood, like under the victim's fingernails, DNA fingerprinting is useful in forensics. Forensics is the scientific investigation of the causes of injury and death when criminal activity is suspected, like in this case.
b. How could you test one of these issues using DNA fingerprinting without using blood samples from the scene of the crime.
My answer: You can check if the 2 men are brothers by comparing their banding patterns.
Are my answers OK?
Thanks
-MC