Biotechnology Principles and Processes NEET Questions pdf: Answer Key, FAQs

Recombinant DNA technology is an effective approach that allows scientists to manipulate and combine DNA from different organisms to create new genetic combinations. This technology is based on several key tools:

1. Restriction Enzymes

Molecular Scissors: These enzymes act as molecular scissors, cutting DNA molecules at precise nucleotide sequences called restriction sites.

Types of Cuts:

• Sticky ends: Staggered cuts that leave short, single-stranded overhangs.
• Blunt ends: Straight cuts that produce double-stranded ends.

Applications:

• Generating DNA fragments of specific sizes.
• Creating compatible ends for DNA ligation.

2. Polymerase Chain Reaction (PCR)

DNA Amplification: PCR is a technique used to amplify specific DNA sequences exponentially.

Process:

• Denaturation: Heating the DNA to separate the strands.
• Annealing: Cooling the DNA to allow primers to bind to complementary sequences.
• Extension: Extending the primers using DNA polymerase to synthesize new DNA strands.

Applications:

• DNA cloning.
• Genetic testing.
• Forensic science.

3. Vectors

DNA Carriers: Vectors are DNA molecules that can carry foreign DNA into a host cell.

Types of Vectors:

• Plasmids: Small, circular DNA molecules that replicate independently of the host chromosome.
• Bacteriophages: Viruses that infect bacteria and can be used to introduce foreign DNA into bacterial cells.

Key Features of Vectors:

• Origin of replication (ori): Ensures replication of the vector.
• Selectable marker: Gene that confers resistance to antibiotics or other selective agents.
• Multiple cloning sites (MCS): Region with multiple restriction enzyme sites for inserting foreign DNA.

4. Gene Cloning

Creating DNA Copies: Gene cloning involves creating multiple identical copies of a specific gene.

Process:

• Isolation of DNA: Extracting the desired gene from the source organism.
• Insertion into Vector: Inserting the gene into a suitable vector using restriction enzymes and DNA ligase.
• Transformation: Introducing the recombinant DNA into a host cell.
• Selection and Amplification: Selecting transformed cells and amplifying the cloned gene.