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प्रश्न
Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.
Name and describe the technique that helps in the separation and isolation of DNA fragments.
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उत्तर
Gel electrophoresis is a technique which is used for separating DNA fragments in a gel on the basis of their electric charge and size.
The process of gel electrophoresis is as follows:
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The fragments obtained after cutting with restriction enzymes are separated by using gel electrophoresis.
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Electric field is applied to the agarose gel matrix and the negatively-charged DNA fragments move towards the anode.
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Fragments separate according to their size by the sieving properties of agarose gel. The smaller the fragment, the farther it moves.
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Staining dyes such as ethidium bromide, upon exposure to UV radiation, are used to visualise the DNA fragments.
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DNA fragments are visible as bright orange-coloured bands in the agarose matrix.
- These bands are cut from the agarose gel and extracted from the gel piece (elution).
- DNA fragments are purified and used in constructing recombinant DNAs
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
Give an example of the source of thermostable enzyme DNA polymerase.
One of the major contributions of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.
Expand the following abbreviation: BAC
Enlist different types of restriction enzymes commonly used in rDNA technology? Write about their role.
ECoRI is obtained from ______.
What is gene cloning? Explain different tools used for it.
What is Recognition sequence? Explain in brief.
The following identifies the major features of technology that differentiate modem biotechnology from classical biotechnology.
i. Capability of science to change the genetic material for getting new specific products through rDNA technology, polymerase chain reaction (PCR), microarrays, cell culture and fusion, and bioprocessing.
ii. Ownership of technology and its sociopolitical impact.
iii. Modem biotechnology makes use of only fermentation technology.
iv. Classical biotechnology relies only on principles of plant and animal tissue culture.
What is true for plasmid?
Name a recombinant vaccine that is currently being used in vaccination programme.
What would happen when one grows a recombinant bacterium in a bioreactor but forget to add antibiotic to the medium in which the recombinant is growing?
Which vector is mostly used in rDNA technology in plants?
Name two restriction enzymes used in PCR.
Identify the desirable characteristics for a plasmid used in rDNA technology from the following.
- Ability to multiply and express outside the host in a bioreactor.
- A highly active promoter.
- A site at which replication can be initiated.
- One or more identifiable marker genes.
- One or more unique restriction sites.
pBR322, used very frequently in cloning experiments as a vector in E. coli is ______.
Explain the mechanism of PCR.
Importance of PCR.
Give a reason for the following:
DNA cannot enter directly into the host cell.
Suneeta is planning an experiment to clone a gene in a vector. So, she has to choose a good cloning vector.
Which one of the vectors shown below should she choose? Justify your answer by giving two reasons.
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 |
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| Vector A | Vector B | Vector C |
