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प्रश्न
Explain briefly:
Restriction enzymes and DNA
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उत्तर
Restriction enzymes belong to a larger class of enzymes called nucleases. They are mainly classified into two types:
- Exonucleases: They remove nucleotides from the terminal ends of the DNA molecule.
- Endonucleases: They make cuts at specific positions anywhere within the DNA molecule.
Restriction endonucleases are a specific class of endonucleases that recognise palindromic nucleotide sequences and cleave DNA at specific sites. They cut both strands of the DNA double helix at specific points to generate sticky or blunt ends, which are essential for creating recombinant DNA.
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संबंधित प्रश्न
Suggest a technique to a researcher who needs to separate fragments of DNA.
Name the enzymes that are used for the isolation of DNA from bacterial and fungal cells for recombinant DNA technology.
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.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
'Restriction' in restriction enzyme refers to
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
Which of the following bacteria is not a source of restriction endonuclease?
Would you choose an exonuclease while producing a recombinant DNA molecule?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
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?
How does one visualise DNA on an agarose gel?
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?
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?
State the importance of elution in this process.
State the principle involved in separation of DNA fragments using gel electrophoresis.
How are DNA fragments visualised once they are separated by gel electrophoresis?
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?
Which of the following represents the specific palindromic recognition sequence cleaved by the restriction endonuclease EcoRI?
Why is it mandatory to cut both the vector DNA and the foreign source DNA with the exact same restriction enzyme when constructing recombinant DNA?
During agarose gel electrophoresis, why do DNA fragments migrate toward the anode (positive electrode)?
According to the sieving effect of an agarose gel matrix, which DNA fragments move the farthest and fastest from the loading wells?
Why are Type II restriction endonucleases the primary class of restriction enzymes used in genetic manipulation?
