Practice question

Forensic identification demands markers with many alleles, high heterozygosity, small amplicon size suitable for degraded DNA, and uniform genomic distribution. Short Tandem Repeats fulfill these criteria because replication slippage generates extensive polymorphism, with heterozygosity often exceeding 70 percent. Multiple unrelated individuals rarely share complete STR profiles, giving high power of discrimination and low random match probability. Low mutation rate or stability would reduce informativeness, while low assay cost is beneficial but not primary. High polymorphism ensures uniqueness of profiles, essential for criminal casework and parentage testing.