(a) Differentiate between repetitive and satellite DNA.
(b) How can satellite DNA be isolated ? Explain.
(c) List two forensic applications of this technology. (5 marks)
Repetitive DNA Satellite DNA
These are the sequences in which a small When repetitive DNA is seperated from bulk geno-
stretch of DNA is repeated many times. mic DNA as different peaks during density gradient
centrifugation, satellite DNA forms minor peaks.
(b) Repetitive DNA are seperated from bulk genomic DNA as different peaks during density
gradient centrifugation. The bulk DNA forms a major peak and the other small peaks are called
(c) (i) DNA fingerprinting is the basis of paternity testing, in case of disputes.
(ii) DNA fingerprinting is used for evidence in criminal cases.
Depending on the base composition A : T rich or G : C rich length of segment, and number of repe-
titive units, satellite DNA are of different types micro-satellites, mini-satellites etc.