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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?

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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

MCQ
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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.

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अध्याय 11: Biotechnology : Principles and Processes - MULTIPLE CHOICE QUESTIONS [पृष्ठ ७५]

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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.


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Explain briefly:

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Explain the roles of the following with the help of an example each in recombinant DNA technology :

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Applying Chargaff’s rule, what conclusion can be drawn?


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?


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'Restriction' in restriction enzyme refers to


A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is ______


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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?


CTTAAG
GAATTC

  1. What are such sequences called? Name the enzyme used that recognizes such nucleotide sequences.
  2. 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?


What is elution?


'EcoRI' has played a very significant role in rDNA technology.

  1. Explain the convention for naming EcoRI.
  2. Write the recognition site and the cleavage sites of this restriction endonuclease.

Identify the activity of endonuclease and exonuclease in the given image.


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