Question

Satellite DNA is a useful tool in
a. Organ transplantation
b. Sex determination
c. Forensic Science
d. Genetic engineering

Answer 1

Hint: Satellite DNA is useful in forensic science. The polymorphism of minisatellite, microsatellite and minivarient repeats is analysed for DNA fingerprinting, DNA profiling. It helps in the resolution of crimes, legal disputes etc.

Complete answer:
Human genome possesses numerous small non-coding but inheritable sequences of bases which are repeated many times. The region with the same sequence of bases repeated several times is known as repetitive DNA. They can be separated as satellites from the bulk DNA during density gradient centrifugation and therefore called satellite DNA.

In satellite DNA, repetition of bases is present in tandem. Depending upon base composition, length and numbers of tandemly repetitive units, satellite DNA is further subdivided into various categories like microsatellites and minisatellites. Satellite DNAs show polymorphism.

The word polymorphism is commonly used when a variant at a locus is present with a frequency of more than 0.01 population. Tandemely repeating DNAs and the variation between them (polymorphisms) is the basis of many DNA profiling techniques. This is because of the number and location of these polymorphisms that every individual has unique DNA that produces a unique band pattern when analysed. It is considered as the foundation of the extensive study of the genome that DNA fingerprinting has been produced as a useful and reliable technique in forensic science.

Hence, the correct answer is option (C).

Note: Since DNA extracted from every tissue (e.g., blood, hair follicle, skin, bone, saliva, sperm etc.) from an individual show the same degree of polymorphism. DNA polymorphism is the basis of genetic mapping of the human genome as well as becoming a very useful identification tool in forensic application.