Question

Some highly degraded DNA was collected from a crime scene. Upon analysis, forensic scientists were only able to accurately sequence one 450-nucleotide-long segment of DNA from a Y chromosome. There are five suspects in the case, but they have fled the state. However, they all have large extended families in the area. How can the police narrow the search to just one suspect?

Answer 1

The correct answer is:

It's necessary to collect DNA from male siblings, fathers, or paternal grandfathers

Step-by-step explanation:

This happens because a parent gives half their DNA to their child. This means that when 10 STRs are studied, at least 10 bands will be identical on a gel comparing one parent and child. The Y chromosomal DNA is passed on from father to son, so it represents a nearly unbroken chain that moves through all recorded history.