Advertisements
Advertisements
Question
Answer the following question.
β galactosidase enzyme is considered a better selectable marker. Justify the statement.
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Can you think and answer how a reporter enzyme can be used to monitor the transformation of host cells by foreign DNA in addition to a selectable marker?
Write the role of ‘restriction sites’ in the cloning vector pBR322.
Explain the importance of ‘Selectable marker’, with the help of a suitable example.
Answer the following question.
Expand ‘YAC’ and mention what it was used for.
A clone is a ______.
Which of the following statement is not true for a clone?
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.
Name the regions marked A, B and C.

The following diagram showing restriction sites in E. coli cloning vector pBR322. Find the role of ‘X’ and ‘Y’ genes:

