Final answer:
Short tandem repeats (STRs) are sequences in DNA that differ between individuals, making them useful for identification in forensic science and genetic relatedness studies. Unique STR patterns can be amplified and identified through techniques such as PCR and gel electrophoresis, providing a highly reliable method for individual identification, except in the case of identical twins.
Step-by-step explanation:
STR, short tandem repeat, in both forensic science and genetic relatedness studies are used to identify an individual.
Short tandem repeats (STRs) are specific sequences in DNA that are repeated multiple times. These STR sequences vary greatly from individual to individual, which makes them ideal for DNA profiling in fields such as forensic science, paternity testing, and personal identification. Restriction Fragment Length Polymorphism (RFLP), Variable Number of Tandem Repeats (VNTRs), and Single Nucleotide Polymorphisms (SNPs) are other genetic markers used in generating genetic maps.
The principle behind using STRs for identification lies in the genetic variation between individuals. Each person has unique STR patterns that can be amplified using Polymerase Chain Reaction (PCR) and then identified through methods such as gel electrophoresis. Identical twins are an exception as they share the same STR sequences, but aside from them, the likelihood of two individuals having the same STR pattern is extremely low, which is why STR analysis is so powerful in identifying individuals.