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प्रश्न
Distinguish between exonuclease and endonuclease.
Differentiate between exonuclease and endonuclease.
Discuss with your teacher and find out how to distinguish between exonuclease and endonuclease.
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उत्तर
| Sr. No. | Exonuclease | Endonuclease |
| 1. | It is a type of restriction enzyme that removes the nucleotide from the 5' or 3' ends of the DNA molecule. | It is a type of restriction enzyme that makes a cut within the DNA at a specific site to generate sticky ends. |
| 2. | They separated DNA base pairs at their terminal ends.![]() |
They separate DNA at any location other than the terminal ends.![]() |
| 3. | They work on single strands of DNA or gaps in double-stranded DNA. | They cut one or both strands of double-stranded DNA. |
APPEARS IN
संबंधित प्रश्न
How are 'sticky ends' formed on a DNA strand? Why are they so called?
Why is the enzyme cellulase needed for isolating genetic material from plant cells and not form the animal cells?
Mention the difference in the mode of action of exonuclease and endonuclease.
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.
Write the use of restriction endonuclease in the formation of recombinant DNA.
Give a reason why :
Single cloning site is preferred in a vector.
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 ______.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
Molecular scissors, which cut DNA at specific site is ______.
DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as ______
Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
While isolating DNA from bacteria, which of the following enzymes is not required?
Which of the following statements does not hold true for restriction enzyme?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
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.
A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?
CTTAAG
GAATTC
- What are such sequences called? Name the enzyme used that recognizes such nucleotide sequences.
- What is their significance in biotechnology?
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?
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.
Identify the activity of endonuclease and exonuclease in the given image.


