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प्रश्न
Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?
विकल्प
Endonuclease
Exonuclease
DNA ligase
Hind - II
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उत्तर
Exonuclease
Explanation:
The enzyme that catalyzes the removal of nucleotides from the ends of DNA is exonuclease. Exonuclease specifically removes nucleotides one by one from the ends of a DNA strand, whereas endonucleases cut DNA at internal sites. DNA ligase joins DNA fragments but does not remove nucleotides. Hind II is a type of restriction endonuclease that cuts DNA at specific internal sequences, not at the ends.
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.
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.
Do eukaryotic cells have restriction endonucleases? Justify your answer.
Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.
Distinguish between exonuclease and endonuclease.
How does restriction endonuclease function?
Explain the roles of the following with the help of an example each in recombinant DNA technology :
Restriction Enzymes
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?
'Restriction' in restriction enzyme refers to
DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as ______
A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is ______
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
'Restriction' in Restriction enzyme refers to ______.
While isolating DNA from bacteria, which of the following enzymes is not required?
Which of the following bacteria is not a source of restriction endonuclease?
Which of the following statements does not hold true for restriction enzyme?
Would you choose an exonuclease while producing a recombinant DNA molecule?
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.
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 stepwise schematic representation of the process of electrophoresis. Identify the 'alphabets' representing
- Anode end
- smallest/lightest DNA strand in the matrix
- Agarose gel
What is elution?
State the importance of elution in this process.
State the principle involved in separation of DNA fragments using gel electrophoresis.
