Question

Each of the 13 STR bands must match

What must match in forensic analysis?
a) Fingerprints
b) DNA STR bands
c) Hair samples
d) Footprints

Answer 1

In forensic analysis, each of the 13 STR bands of a DNA profile must match when comparing samples from a crime scene with those from suspects or victims to determine involvement in the crime or establish familial relationships.

Step-by-step explanation:

Matching DNA STR Bands in Forensic Analysis

In forensic analysis, specifically when it comes to DNA fingerprinting, each of the 13 STR (Short Tandem Repeat) bands must match between the DNA profile obtained from a crime scene and the DNA profiles of potential suspects or victims. This advanced technique is part of forensic sciences and involves collecting DNA samples, PCR amplification, restriction enzyme digestion, and electrophoresis to create unique DNA banding patterns. These patterns are compared against existing profiles to establish a DNA match, which can be crucial in crime-solving and establishing family relationships.

When establishing a child's relation to his or her parents, the child's DNA fingerprint must have STR bands that are consistent with a combination of the mother's and father's DNA profiles. In the case of forensic geneticists analyzing a crime scene, if the DNA at the scene matches exactly the DNA of a suspect, it could be strong evidence pointing to the involvement of that individual.

Answer 2

In forensic analysis, DNA STR bands must match between the crime scene samples and the suspect or victim samples to establish identity or relation. This is achieved through PCR amplification and gel electrophoresis. The STR bands are critical for making connections in criminal investigations.

Step-by-step explanation:

In forensic analysis, when dealing with DNA evidence, DNA STR bands must match between samples collected from a crime scene and those collected from suspects or victims. This matching is essential for establishing identities and connections in forensic cases. The process involves PCR amplification of STR (short tandem repeat) loci and comparing the banding patterns generated from agarose gel electrophoresis. For instance, to establish a child's relationship to their parents, the child's DNA fingerprint, which includes these STRs, should have similarities to the DNA of both the mother and the father, with each parent contributing to half of the STRs.

Forensic scientists utilize various forms of DNA analysis, such as RFLP analysis, PCR, and sequencing, to make these matches. In addition to STR band matching, mitochondrial DNA sequencing can be employed, albeit less commonly, in forensic analysis. Forensic geneticists can definitively determine whether a sample from a crime scene matches the DNA of a suspect, thus playing a critical role in the criminal justice system.