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प्रश्न
What is PCR? Explain different steps involved in it.
उत्तर
Definition: Polymerase Chain Reaction (PCR) is the process of in vitro amplification of gene of interest using a PCR machine.
Mechanism of PCR: At the start of PCR, all the requirements are mixed together in ‘eppendorf tube’ and the following operations are performed sequentially:
Step i: Denaturation
The reaction mixture is heated to a temperature (90–98o C) to separate two strands of desired DNA. This is called denaturation.
Step ii: Annealing
The mixture is allowed to cool (40–60o C) that permits pairing of the primer to the complementary sequences in DNA. This step is called annealing.
Step iii: Primer extension / Polymerization
The temperature (70–75o C) allows thermostable Taq DNA polymerase to use single-stranded DNA as template and adds nucleotides. This is called primer extension. It takes around two minutes duration.
संबंधित प्रश्न
Rearrange the following in the correct sequence to accomplish an important biological reaction:
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA
State the role of DNA ligase in biotechnology.
What is the cell that receives a recombinant gene called?
The enzyme nuclease hydrolyses ______ of polynucleotide chain of DNA.
Bt-cotton shows adverse effect on the population of which butterfly?
Identify the CORRECT sequence of steps in PCR.
Study the following statements regarding separation of DNA using agarose gel electrophoresis.
- Large fragments of DNA molecules move faster than small DNA fragments and thus separate faster.
- DNA being negatively charged migrates to cathode.
Who among the following was awarded the Nobel Prize for the development of PCR technique?
Which of the following enzyme catalyses the removal of nucleotides from the end of DNA molecules?
______technique is used for in vitro gene cloning or gene multiplication.
