What are DNA polymorphisms and how do they differentiate between people?
(Source – The Hindu, International Edition – Page No. – 11)
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Topic: GS3 – Science and Technology |
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Context |
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What is DNA?
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DNA is present in almost all cells of the body, such as skin, blood, and bones.
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Each person has 46 DNA molecules: 23 from the father and 23 from the mother.
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DNA is packed into chromosomes, with chromosome 3 containing 6.5% of total DNA.
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DNA remains intact for thousands of years, with some samples preserved for 65,000 years.
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DNA Polymorphism |
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What are STRs (Short Tandem Repeats)?
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STRs are short sequences of DNA bases repeated multiple times.
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These sequences vary among individuals, making them useful for identification.
How is DNA copied?
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Scientists use Polymerase Chain Reaction (PCR) to make copies of specific DNA segments.
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PCR involves heating, cooling, and using enzymes like DNA polymerase to replicate DNA quickly.
What is a DNA fingerprint?
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A unique DNA profile is created using capillary electrophoresis, which separates DNA based on size.
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This fingerprint can be obtained from teeth, bones, blood, saliva, and skin cells.
Uses of DNA Fingerprinting
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Forensic investigations – Identifies suspects using DNA from crime scenes.
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Disaster victim identification – Helps recognize remains at disaster sites.
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Parentage testing – Establishes parent-child relationships.
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Organ donation matching – Confirms compatibility between donors and recipients.
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Solving old cases – DNA from archives helps resolve past crimes.
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Exonerating wrongfully convicted individuals – Clears innocent people of false charges.
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Practice Question: Discuss the significance of DNA fingerprinting in forensic investigations and biological identification. Highlight its applications, challenges, and ethical concerns. (150 Words /10 marks) |
