Advertisements
Advertisements
Questions
Would you choose an exonuclease while producing a recombinant DNA molecule?
Would you like to choose an exonuclease enzyme while producing a recombinant DNA molecule?
Advertisements
Solution
No, as exonuclease acts on the free ends of linear DNA molecule. Therefore, instead of producing DNA fragments with sticky ends, it will shorten or completely degrade the DNA fragment containing the gene of interest, and the circular plasmid (vector) will not get cut as it lacks free ends.
APPEARS IN
RELATED QUESTIONS
Make a chart (with diagrammatic representation) showing a restriction enzyme, the substrate DNA on which it acts, the site at which it cuts DNA and the product it produces.
Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.
Distinguish between exonuclease and endonuclease.
Explain the roles of the following with the help of an example each in recombinant DNA technology :
Restriction Enzymes
Answer the following question.
Write the use of restriction endonuclease in the formation of recombinant DNA.
Give a reason why :
Single cloning site is preferred in a vector.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
DNA fragments separate according to size through?
The role of DNA ligase in the construction of a recombinant DNA molecule is ______.
Which of the following bacteria is not a source of restriction endonuclease?
Which of the following statements does not hold true for restriction enzyme?
Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.
Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at ‘specific-recognition sequence’. What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?
A plasmid DNA and a linear DNA (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.
How does one visualise DNA on an agarose gel?
What is elution?
Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule.
\[\ce{5' C - T - G - C - A \overset{\downarrow}{-}{G 3'}}\]
\[\ce{3' G\underset{\uparrow}{-} A - C - G - T - C 5'}\]
Choose the option that gives the correct resultant fragments by the action of the enzyme Pst-I.
'EcoRI' has played a very significant role in rDNA technology.
- Explain the convention for naming EcoRI.
- Write the recognition site and the cleavage sites of this restriction endonuclease.
How are DNA fragments visualised once they are separated by gel electrophoresis?
Identify the activity of endonuclease and exonuclease in the given image.
Hind II always cuts DNA molecules at a particular point called recognition sequence and it consists of ______.
Which of the following was the very first restriction endonuclease to be isolated and characterized?
How do exonucleases differ fundamentally from endonucleases in their enzymatic site of action?
What is the origin of agarose, the matrix most commonly used in gel electrophoresis?
According to the sieving effect of an agarose gel matrix, which DNA fragments move the farthest and fastest from the loading wells?
