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प्रश्न
Do eukaryotic cells have restriction endonucleases? Justify your answer.
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उत्तर
Yes, restriction endonucleases are found in eukaryotic cells. Restriction endonuclease acts by examining the length of the DNA sequence. When it finds its specific recognition sequence, it binds to the DNA and cuts both strands of the double helix at specific points in the sugar-phosphate backbones. Each restriction endonuclease recognises specific palindromic nucleotide sequences in DNA.
संबंधित प्रश्न
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.
How does a restriction nuclease function? Explain
Explain briefly:
Restriction enzymes and DNA
Distinguish between exonuclease and endonuclease.
Answer the following question.
Explain the significance of palindromic nucleotide sequence in the formation of recombinant DNA.
Answer the following question.
Write the use of restriction endonuclease in the formation of recombinant DNA.
DNA fragments separate according to size through?
Which of the following statements does not hold true for restriction enzyme?
Would you choose an exonuclease while producing a recombinant DNA molecule?
Restriction enzymes should not have more than one site of action in the cloning site of a vector. Comment.
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?
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?
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.
How are DNA fragments visualised once they are separated by gel electrophoresis?
Identify the activity of endonuclease and exonuclease in the given image.
