Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
It is because plasmid is a circular DNA molecule. When cut with enzyme, it becomes linear but does not get fragmented. Whereas, a linear DNA molecule gets cut into two fragments. Hence, a single DNA band is observed for plasmid while two DNA bands are observed for linear DNA in agarose gel.

APPEARS IN
संबंधित प्रश्न
Mention the difference in the mode of action of exonuclease and endonuclease.
How does a restriction nuclease function? Explain
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.
Explain briefly:
Restriction enzymes and DNA
Answer the following question.
Explain the significance of palindromic nucleotide sequence in the formation of recombinant DNA.
The DNA fragment separated on an agarose gel can be visualized by staining with ______.
A mixture containing DNA fragments a, b, c and d, with molecular weights of a + b = c, a > b and d > c was subject to agarose get electrophoresis. This position of these fragments from cathode to anode to anode sides of the gel would be ______.
Which of the following radioisotope is not suitable for DNA labeling based studies?
Restriction enzymes ______.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
DNA fragments separate according to size through?
Which of the following bacteria is not a source of restriction endonuclease?
Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.
Carefully observe the given picture. A mixture of DNA with fragments ranging from 200 base pairs to 2500 base pairs was electrophoresed on agarose gel with the following arrangement.

(a) What result will be obtained on staining with ethidium bromide? Explain with reason.
(b) The above setup was modified and a band with 250 base pairs was obtained at X.

What change(s) were made to the previous design to obtain a band at X? Why did the band appear at position X?
What is elution?
State the importance of elution in this process.
What are the protruding and hanging stretches of DNA produced by these restriction enzymes called? Describe their role in the formation of rDNA.
How are DNA fragments visualised once they are separated by gel electrophoresis?
