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प्रश्न
Explain briefly:
PCR
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उत्तर
PCR (Polymerase Chain Reaction) is a technique used to create multiple copies of a specific DNA segment in vitro. It amplifies DNA by repeated cycles of three steps:
- Denaturation: Heating the double-stranded DNA to around 94°C to separate it into single strands.
- Annealing: Cooling to 46-60°C to allow short primers to bind to complementary sequences on the single-stranded DNA.
- Extension: Raising the temperature to about 72°C so a heat-stable DNA polymerase (Taq polymerase) synthesizes new complementary strands, duplicating the target DNA.
Repeating these cycles exponentially amplifies the DNA segment, producing millions of copies rapidly. PCR is widely used for DNA amplification, genetic fingerprinting, disease detection, DNA sequencing, and molecular mapping. It was introduced by Kary Mullis in 1985 and relies on the thermostable enzyme from Thermus aquaticus to function at high temperatures without being denatured.
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संबंधित प्रश्न
Name two commonly used bioreactors.
Draw a labelled sketch of sparged-stirred-tank bioreactor. Write its application.
Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?
Can you recall meiosis and indicate at what stage recombinant DNA is made?
State the importance of using a bioreactor.
Answer the following question:
Describe the formation of recombinant DNA by the action of EcoRI.
Which of the following term used for defining a viral genome incorporated into host DNA?
______ plays an important role in blood clotting.
DNA fragments generated by the restriction endonuclease in a chemical reaction can be separated by ______.
A single strand of nucleic acid tagged with a radioactive molecule is called ______.
Gene Amplification using primers can be done by ______.
PCR proceeds mthree distinct steps governed by temperature, they are in order of ______.
The first step in recombinant DNA technology is
In addition to the Taq polymerase enzyme, which other thermostable DNA polymerases have been isolated to be used in PCR?
In PCR, primers are used for ______.
An antibiotic resistance gene in a vector usually helps in the selection of ______.
Which of the following steps are catalysed by Taq DNA polymerase in a PCR reaction?
A bacterial cell was transformed with a recombinant DNA molecule that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be ______.
Which of the following should be chosen for best yield if one were to produce a recombinant protein in large amounts?
Identify and explain steps ‘A’, ‘B’ and ‘C’ in the PCR diagram given below.
Illustrate the design of a bioreactor. Highlight the difference between a flask in your laboratory and a bioreactor which allows cells to grow in a continuous culture system.
Assertion (A): Synthetic oligonucleotide polymers are used during Annealing in a PCR.
Reason (R): The primers bind to the double stranded DNA at their complementary regions.
State the advantage of using Thermostable DNA polymerase.
Bioreactors are the containment vehicles of any biotechnology-based production process. For large scale production and for economic reasons the final success of biotechnological process depends on the efficiency of the bioreactor.
Answer the following questions w.r.t. the given paragraph:
- List the operational guidelines that must be adhered to so as to achieve optimisation of the bioreactor system. Enlist any four.
- Mention the phase of the growth we refer to in the statement "Optimisation of growth and metabolic activity of the cells".
- Is the biological product formed in the bioreactor suitable for the intended use immediate? Give reason in support of your answer.
