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प्रश्न
Describe the role of CaCl2 in the preparation of competent cells?
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उत्तर
CaCl2 is known to increase the efficiency of DNA uptake to produce transformed bactrial cells. The divalent Ca+2 ions supposedly create transient pores on the bactrial cell wall by which the entry of foreign DNA is facilitated into the bactrial cells.
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संबंधित प्रश्न
Name the selectable markers in the cloning vector pBR322. Mention the role they play.
What is ‘Ori’ ? State its importance during cloning of a vector.
Answer the following question.
Expand ‘YAC’ and mention what it was used for.
How does the β-galactosidase coding sequence act as a selectable marker? Why is it a preferred selectable marker to antibiotic resistance genes? Explain.
Which of the following statement is not true for a clone?
Plasmids are suitable vectors for gene cloning because these ______.
A cloning vector should possess which of the following characters?
- Origin of replication (Ori)
- Ability to destroy the alien DNA
- Cloning site to link the alien DNA
- The tumour inducing plasmid Ti.
- Selectable marker.
- Low molecular weight
The CORRECT combination is
Which of the following is not a cloning vector?
Plasmid pBR322 has a PstI restriction enzyme site within gene ampR that confers ampicillin resistance. If this enzyme is used for inserting a gene for β-galactoside production and the recombinant plasmid is inserted in an E.coli strain.
What does ‘competent’ refer to in competent cells used in transformation experiments?
What modification is done on the Ti plasmid of Agrobacterium tumefaciens to convert it into a cloning vector?
Name the regions marked A, B and C.
For selection of recombinants, insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate.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.
Which of the following enzyme(s) are NOT essential for gene cloning?
- Restriction enzymes
- DNA ligase
- DNA mutase
- DNA recombinase
- DNA polymerase
Choose the correct answer from the options given below:
