Advertisements
Advertisements
प्रश्न
Explain briefly:
Restriction enzymes and DNA
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Explain with the help of a suitable example the naming of a restriction endonuclease.
How are 'sticky ends' formed on a DNA strand? Why are they so called?
Name the enzymes that are used for the isolation of DNA from bacterial and fungal cells for recombinant DNA technology.
How does a restriction nuclease function? Explain
Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.
Distinguish between exonuclease and endonuclease.
Answer the following question.
Explain the significance of palindromic nucleotide sequence in the formation of recombinant DNA.
The DNA fragment separated on an agarose gel can be visualized by staining with ______.
Restriction enzymes ______.
'Restriction' in restriction enzyme refers to
DNA fragments separate according to size through?
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?
Which of the following statements does not hold true for restriction enzyme?
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 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?
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 are the protruding and hanging stretches of DNA produced by these restriction enzymes called? Describe their role in the formation of rDNA.
How are DNA fragments visualised once they are separated by gel electrophoresis?
