સેટેલાઇટ \(DNA\) એ મહત્ત્વનું છે. કારણ કે તે .........

(d) : Satellite \(DNA\) is that part of repetitive \(DNA\) which has long repetitive nucleotide sequences in tandem that forms a separate fraction on density ultracentrifugation. \(DNA\) fingerprinting involves identifying differences in some specific regions in \(DNA\) sequence called as repetitive \(DNA\), because in these sequences, a small stretch of \(DNA\) is repeated many times. These repetitive \(DNA\) sequences are separated from bulk genomic \(DNA\) as different peaks during density gradient centrifugation. The bulk \(DNA\) forms a major peak and the other small peaks are referred to as satellite \(DNA\). Depending on base composition \((A:T\) rich or \(G:C\) rich), length of segment, and number of repetitive units, the satellite \(DNA\) is classified into many categories, such as micro­ satellites, mini­satellites etc. These sequences normally do not code for any proteins, but they form a large portion of human genome. These sequences show high degree of polymorphism and form the basis of \( DNA\) fingerprinting. Since \(DNA\) from every tissue (such as blood, hair­follicle, skin, bone, saliva, sperm etc.) from an individual show the same degree of polymorphism, they become very useful identification tool in forensic applications.