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प्रश्न
A PCR machine can raise the temperature up to 100°C but after that, it is not able to lower the temperature below 70°C automatically. Which step of PCR will be hampered first in this faulty machine? Explain why?
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उत्तर
i. If a PCR machine fails to lower the temperature below 70°C then the annealing step (in which primers attach to the respective ends of the DNA template) would be affected.
ii. The annealing step of PCR requires a temperature ranging between 40°C to 60°C therefore if a PCR machine fails to lower the temperature below 70°C, primers will not attach to the DNA templates.
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संबंधित प्रश्न
What is gene cloning? Explain different tools used for it.
Which of the following device is required for PCR?
What is true for plasmid?
What is the significance of adding proteases at the time of isolation of genetic material (DNA)?
Cloning of genes, play a very significant role in genetic engineering, helping the transfer of desirable foreign genes into different hosts. The scientists, to make this process easier and effective are creating engineered vectors in such a way that they help easy linking of foreign DNA and selection of recombinants from non-recombinants. 'pBR322' is one such engineered vectors developed by scientists. A diagram of an engineered vector pBR322 is given below:
- Name the host for this cloning vector.
- Identify 'Rop' and 'Ori' in the diagram from 'U', 'V', 'W', 'X', 'Y' and 'Z'. Write their functions.
- Draw the fragments that will be formed by the action of 'Z' (marked in the diagram) on the specific site of the DNA segment given below:
5' --- GTACGAATCCTGA --- 3'
3' --- CATGCTTAGGACT --- 3'
Which of the following statements are true about cloning vectors?
- Vectors are DNA molecules that carry a foreign DNA segment.
- The replicated DNA is introduced into the host cell.
- It possesses the origin of replication (Ori).
- Vectors may be plasmid, bacteriophage, Yeast artificial chromosomes (YACs), etc.
- Vectors do not require a selectable marker to identify and eliminate non-transformants.
Choose the correct answer from the options given below.
pBR322, used very frequently in cloning experiments as a vector in E. coli is ______.
The structure below shows pUC18, which is similar to pBR322 in its function. However, they differ in some of their restriction sites and the number of ori. The ori number for pBR322 is approximately 20.
- How are puc18 and pBR322 used in biotechnological studies?
OR
What will be the impact if the ori in the above structure gets damaged? - The lac z gene has many recognition sites. Study the segment of DNA given below and answer the questions.
5’... ATC GTA AAG CTT CAT…3’
3’... TAG CAT TTC GAA GTA…5’
i) Applying your knowledge of palindrome sequences identify and mark the possible region where the restriction enzyme X will act.
ii) Restriction enzyme Y was used to extract a gene of interest from a plant. This gene needs to be inserted in the given DNA segment which has been treated with restriction enzyme X. Will there be a successful recombination? Explain with a reason. - Which one of the two (pUC18 and pBR322) would you prefer for biotechnological studies? Justify.
Name the source of thermostable DNA polymerase.
Suneeta is planning an experiment to clone a gene in a vector. So, she has to choose a good cloning vector.
Which one of the vectors shown below should she choose? Justify your answer by giving two reasons.
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| Vector A | Vector B | Vector C |
