Question

What i s dna fingar printing?

Answer 1

DNA fingerprinting is a method for comparing the DNA sequences of any two individuals.

99.9% of the base sequences in all human beings are identical. It is the remaining 0.1% that makes every individual unique.

It is a really difficult and time-consuming task to sequence and compare all 3 × 109 bases in two individuals. So, instead of considering the entire genome, certain specific regions called repetitive DNA sequences are used for comparative study.

Basis of DNA Fingerprinting

Repetitive DNA is separated from bulk genomic DNA since it appears as a distinct peak during density gradient centrifugation.

Major peak: Formed by bulk DNA
Smaller peak: Satellite DNA

Satellites are of two types—micro-satellites and mini satellites, depending upon the base composition, length of segment and the number of repetitive units.

Satellites do not code for proteins, but have a major role to play in DNA fingerprinting.

Polymorphism is actually a result of mutation. A germ cell mutation (which can pass on to the next generation through sexual reproduction) gives rise to polymorphism in populations.

In other words, an inheritable mutation if observed in higher frequencies in a population is known as polymorphism.

Polymorphisms arise normally in non-coding sequences because mutations in non-coding sequences do not affect an individual’s reproductive ability.

Answer 2

DNA fingerprinting, also called DNA typing, DNA profiling, genetic fingerprinting, genotyping, or identity testing, in genetics, method of isolating and identifying variable elements within the base-pair sequence of DNA (deoxyribonucleic acid). The technique was developed in 1984 by British geneticist Alec Jeffreys, after he noticed that certain sequences of highly variable DNA (known as minisatellites), which do not contribute to the functions of genes, are repeated within genes.