Advertisements
Advertisements
Question
Explain briefly:
PCR
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Name two commonly used bioreactors.
From what you have learnt, can you tell whether enzymes are bigger or DNA is bigger in molecular size? How did you know?
Can you recall meiosis and indicate at what stage recombinant DNA is made?
Explain briefly:
Chitinase
Which of the following term used for defining a viral genome incorporated into host DNA?
PCR and restriction fragment length polymorphism are the methods for ______.
A single strand of nucleic acid tagged with a radioactive molecule is called ______.
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 ______.
During the process of gene amplification using PCR, if a very high temperature is not maintained in the beginning, then which of the following steps of PCR will be affected first?
Rising of dough is due to ______.
Which of the following contributed in popularising the PCR (polymerase chain reactions) technique?
Significance of 'heat shock' method in bacterial transformation is to facilitate ______.
Which of the following steps are catalysed by Taq DNA polymerase in a PCR reaction?
While doing a PCR, ‘denaturation’ step is missed. What will be its effect on the process?
Do biomolecules (DNA, protein) exhibit biological activity in anhydrous conditions?
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.
Read the following paragraph and answer the questions that follow:
| Biotechnology revolves around the "gene of interest", with an objective to open various avenues for human welfare in health, medicine, pharma, agriculture etc. using different techniques, tools and processes. One of the breakthroughs of biotechnology in medicine is the gene therapy. |
- Name the human disease for which the gene therapy was used for the first time.
- Explain the steps of gene therapy carried to cure the disease using the lymphocytes of the patient. Why is this therapy not a permanent cure of the disease?
- Write the possible permanent cure of the disease by the gene therapy that is in progress.
Write the scientific name of the source organism of the thermostable DNA polymerase used in PCR.
Given below are two statements:
Statement I: The DNA fragments extracted from gel electrophoresis can be used in construction of recombinant DNA.
Statement II: Smaller size DNA fragments are observed near anode while larger fragments are found near the wells in an agarose gel.
In the light of the above statements, choose the most appropriate answer from the options given below:
Upon exposure to UV radiation, DNA stained with ethidium bromide will show ______.
