Question

Which procedure would help ensure that a new piece of DNA can be inserted inside a bacterial plasmid when the two are mixed together?
The DNA fragment is pretreated with DNA ligase.
The fragment and plasmid are both cut with the same restriction enzyme.
The plasmid is pretreated with DNA ligase.
The plasmid is modified to contain GFP.

Answer 1

Answer:

The fragment and plasmid are both cut with the same restriction enzyme.

Explanation:

To insert a piece of DNA in a bacterial plasmid, we need to cut both plasmid and DNA insert from same regions. This is typically done by restriction enzymes or restriction endonuclease. This cutting will open the plasmid (which is circular initially) and produce sticky ends. Here, DNA insert can attach because of similar sequence (see attached figure). In the final step, DNA ligase will glue it in the plasmid and it will become its part. This technique has been extensively used as a DNA recombinant technology. A better representation can be seen in the attached figure where both DNA sequence of interest and plasmid are cut with the same restriction enzyme (shown as scissors) and then ligated with DNA ligase.