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प्रश्न
What is ‘Ori’ ? State its importance during cloning of a vector.
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उत्तर
Origin of Replication (Ori):- This is a sequence from where replication starts and any piece of DNA when linked to this sequence can be made to replicate within the host cells.
Importance of Ori:-
(i) It is responsible for controlling the copy number & the linked DNA.
(ii) In cloning if one wants to recover many copies of the target DNA it should be cloned in a vector whose origin supports high copy number.
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संबंधित प्रश्न
Draw a schematic sketch of pBR 322 plasmid and label the following in it:
(a) Any two restriction sites.
(b) Ori and rop genes.
(c) An antibiotic resistant gene.
Describe briefly the following:
Origin of replication
Why is the coding sequence of an enzyme β-galactosidase a preferred selectable marker in comparison to the ones named above?
Write the role of ‘restriction sites’ in the cloning vector pBR322.
How does the β-galactosidase coding sequence act as a selectable marker? Why is it a preferred selectable marker to antibiotic resistance genes? Explain.
Plasmids are suitable vectors for gene cloning because these ______.
Which of the following is not a cloning vector?
A plasmid without a selectable marker was chosen as vector for cloning a gene. How does this affect the experiment?
For selection of recombinants, insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate. Give reasons.
The figure below shows the structure of a plasmid.
A foreign DNA was ligated at BamH1. The transformants were then grown in a medium containing antibiotics tetracycline and ampicillin.
Choose the correct observation for the growth of bacterial colonies from the given table.
