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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
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?
What is ‘Ori’ ? State its importance during cloning of a vector.
Answer the following question.
β galactosidase enzyme is considered a better selectable marker. Justify the statement.
The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of ______.
A clone is a ______.
Plasmids are suitable vectors for gene cloning because these ______.
Which of the following is not a genetic vector?
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 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For selection of recombinants, insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate.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:
Which of the following is not a cloning vector?
