*3.2.1 Variable number of tandem repeats (VNTRs)*

VNTR is among the earliest DND markers in the application. It is a kind of tandem repetitions in which a small order of bases (10–60 base pairs) are frequented changeable times in a certain position. Therefore, VNTR is additionally familiar as minisatellites. Minisatellites are scattered everywhere in the humane DNA. Usually, the number of repeated bases in minisatellites differs among persons. Hence, the array extension shaped by VNTRs as well differs among persons. Accordingly, the variant number of chromosomes is familial from parents, so they can be applied in parental or individual identification. The techniques that use to determine this type are: routines PCR, gel electrophoresis, and amplicons of band designs by southern blotting. The utilization of VNTRs was, nevertheless, restricted by the kind of specimen that could give good results for the reason that a big quantity of DNA was needed. In addition, understanding VNTR profiles might be a difficulty. Their utilization in forensic genomics has been replaced at the present time by short tandem repeats (STRs) [66].

### *3.2.2 Short tandem repeats (STRs)*

Short tandem repeats (STRs) give an extremely good method because of their great grade of polymorphism and a comparatively small length. Additionally, STRs are typical methods for genotyping in the identity of one's parents check and forensic identity check. A category of tandem repeats depended on presents a small order of bases (2–6 base pairs) are frequented a variable number of times in a certain site. STRs are a type of microsatellites, and they are furthermore recognized as short sequence repeats (SSRs) in plant DNA. The repeating bases consist of a single nucleotide that is familiar as a single nucleotide polymorphism (SNP) [66].

#### **3.3 Insertion/deletion polymorphisms**

It is a type of genomic difference in which a particular base order of different sizes ranging from one base to several 100 units is inserted or deleted. Indels are very extending across the DNA. Several writers consider one base pair as SNPs or frequent insertion/deletion as indels [55].
