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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
Explain with the help of a suitable example the naming of a restriction endonuclease.
Mention the difference in the mode of action of exonuclease and endonuclease.
How does a restriction nuclease function? Explain
Name and describe the technique that helps in separating the DNA fragments formed by the use of restriction endonuclease
Do eukaryotic cells have restriction endonucleases? Justify your answer.
How does restriction endonuclease function?
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.
The DNA fragment separated on an agarose gel can be visualized by staining with ______.
A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is ______
In agarose gel electrophoresis, DNA molecules are separated on the basis of their ______.
While isolating DNA from bacteria, which of the following enzymes is not required?
The role of DNA ligase in the construction of a recombinant DNA molecule is ______.
Which of the following bacteria is not a source of restriction endonuclease?
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.
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?
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.
'EcoRI' has played a very significant role in rDNA technology.
- Explain the convention for naming EcoRI.
- Write the recognition site and the cleavage sites of this restriction endonuclease.
State the principle involved in separation of DNA fragments using gel electrophoresis.
How are DNA fragments visualised once they are separated by gel electrophoresis?
Identify the activity of endonuclease and exonuclease in the given image.
