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प्रश्न
Answer the following question.
β galactosidase enzyme is considered a better selectable marker. Justify the statement.
उत्तर
The selective marker is used in the selection of recombinants on the basis of the ability to produce colour in the presence of a chromogenic substrate. β-galactosidase is an enzyme that converts galactose into lactose. In this, a recombinant DNA is inserted within the coding sequence of enzyme, β-galactosidase, which results in inactivation of an enzyme referred to as "insertional inactivation".
The coding sequence for the enzyme β-galactosidase is preferred over antibiotic resistance genes because recombinants can be easily visualized.
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संबंधित प्रश्न
Name the selectable markers in the cloning vector pBR322? Mention the role they play.
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 Ori and 'restriction' site in a 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.
Which of the following is correctly matched?
Plasmids are suitable vectors for gene cloning because these ______.
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For selection of recombinants, insertional inactivation of antibiotic marker has been superceded by insertional inactivation of a marker gene coding for a chromogenic substrate.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.
