Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
If the restriction enzymes would cut DNA at random sites instead of at specific sites, then the DNA fragments obtained will not have ‘sticky ends’. In the absence of sticky ends, construction of recombinant DNA molecules would not be possible.
APPEARS IN
संबंधित प्रश्न
How are 'sticky ends' formed on a DNA strand? Why are they so called?
Mention the difference in the mode of action of exonuclease and endonuclease.
Name the enzymes that are used for the isolation of DNA from bacterial and fungal cells for recombinant DNA technology.
Which of the following radioisotope is not suitable for DNA labeling based studies?
Restriction enzymes ______.
There is a restriction endonudease called as EcoRI. What does co part in it stands for?
'Restriction' in Restriction enzyme refers to ______.
While isolating DNA from bacteria, which of the following enzymes is not required?
What does H in’ ‘d’ and ‘III’ refer to in the enzyme Hind III?
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?
State the importance of elution in this process.
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.
'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.
What are the protruding and hanging stretches of DNA produced by these restriction enzymes called? Describe their role in the formation of rDNA.
State the principle involved in separation of DNA fragments using gel electrophoresis.
During agarose gel electrophoresis, why do DNA fragments migrate toward the anode (positive electrode)?
How are separated DNA bands visualized following agarose gel electrophoresis?
