dna fingerprint

What is DNA fingerprinting?

DNA fingerprinting is a rapid technique used to compare DNA sequences of two individuals. It is based on the uniqueness of each person's DNA, similar to fingerprints.

Why is DNA fingerprinting possible?

DNA fingerprinting is possible because individuals have variations in their nucleotide sequences.

How many pairs of chromosomes are present in humans?

Humans have 23 pairs of chromosomes.

How many pairs of genes are present in humans?

Humans have about 1.5 million pairs of genes.

What are genes?

Genes are segments of DNA that differ in nucleotide sequences and carry information for specific functions.

Do all DNA sequences code for proteins?

No. Some DNA sequences code for proteins, some have regulatory functions, some are introns, and some are repeated DNA sequences.

Which DNA sequences are important in DNA fingerprinting?

Short repetitive nucleotide sequences specific to an individual are important in DNA fingerprinting.

What are VNTRs?

VNTRs (Variable Number Tandem Repeats) are short repetitive nucleotide sequences that vary from person to person.

What is repetitive DNA?

Repetitive DNA consists of sequences where a small stretch of DNA is repeated many times.

Why are repetitive DNA sequences useful in DNA fingerprinting?

They show variation among individuals and help in identification.

How are repetitive DNA sequences separated from genomic DNA?

They are separated from bulk genomic DNA by density gradient centrifugation.

What happens during density gradient centrifugation?

Bulk genomic DNA forms the major peak, while repetitive DNA forms smaller peaks called satellite DNA.

Why is satellite DNA called so?

It forms small separate peaks away from the main DNA peak during density gradient centrifugation.

On what basis is satellite DNA classified?

Satellite DNA is classified based on base composition, length of DNA segment, and number of repetitive units.

Name the types of satellite DNA.

Microsatellites and minisatellites.

What property of satellite DNA forms the basis of DNA fingerprinting?

Satellite DNA shows a high degree of polymorphism.

What is polymorphism?

Polymorphism is variation in DNA sequences among individuals of a population.

Why can small biological samples be used in DNA fingerprinting?

Because every cell contains DNA, small amounts of blood, semen, hair bulb, or other body cells can be used for identification.

Why is DNA fingerprinting useful in forensic science?

It helps identify individuals involved in crimes by comparing DNA samples.

How is DNA fingerprinting useful in paternity testing?

DNA polymorphisms are inherited from parents to children, helping establish biological relationships.

Who developed DNA fingerprinting?

Alec Jeffreys developed the technique of DNA fingerprinting.

What award did Alec Jeffreys receive?

He received the Royal Society's Copley Medal in August 2014.

What is the first step of DNA fingerprinting?

Extraction of DNA from sample cells.

What is amplification?

Amplification is the process of making many copies of DNA.

Which technique is used for DNA amplification?

Polymerase Chain Reaction (PCR).

What happens during restriction digestion?

DNA is cut into smaller fragments using restriction endonucleases.

How are DNA fragments separated?

DNA fragments are separated using gel electrophoresis.

What is Southern blotting?

It is the transfer of separated DNA fragments from gel onto a nylon membrane.

Who invented Southern blotting?

E.M. Southern invented Southern blotting.

What happens during hybridisation?

Labelled VNTR probes attach to specific DNA fragments and unattached probes are washed away.

What are DNA probes?

DNA probes are labelled DNA sequences used to identify specific DNA fragments.

How are DNA fragments detected after hybridisation?

They are detected by exposing them to X-ray film through autoradiography.

What pattern is produced after autoradiography?

A unique pattern of dark and light bands representing an individual's DNA fingerprint.

Why does DNA fingerprint pattern differ among individuals?

Because individuals have different VNTR patterns.

In which case are DNA fingerprints identical?

DNA fingerprints are identical in monozygotic (identical) twins.

How can sensitivity of DNA fingerprinting be increased?

By using Polymerase Chain Reaction (PCR).

How much DNA is sufficient after PCR amplification?

DNA from a single cell is sufficient.

Are only one type of probe used currently?

No, many different probes are used to generate DNA fingerprints.

What are the applications of DNA fingerprinting?

It is used for identification of individuals, establishing relationships, detecting diseases, and studying genetic diversity.

How is DNA fingerprinting used in forensic science?

It identifies criminals by comparing DNA samples from crime scenes with suspects.

How is DNA fingerprinting used in paternity disputes?

It determines biological relationships because DNA is inherited from parents.

How is DNA fingerprinting useful in immigration cases?

It helps prove biological relationships for immigration purposes.

How is DNA fingerprinting used in detecting inherited diseases?

It detects genetic disorders by identifying specific DNA variations.

How is DNA fingerprinting useful in bone marrow transplantation?

It monitors the success of bone marrow transplants by checking donor cells.

How does DNA fingerprinting help study population diversity?

It determines population and genetic diversity by studying DNA variations.

What do dark DNA bands in DNA fingerprints represent?

They represent DNA fragments showing similarities between individuals.

What does a child's DNA fingerprint show in relation to parents?

Children share some DNA bands with their mother and some with their father.