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प्रश्न
Which molecules are called molecular scissors? Why are they called so?
उत्तर
Restriction enzymes are called molecular scissors.
Each restriction endonuclease inspects the length of a DNA sequence. Once it finds its specific recognition sequence, it will bind to the DNA and cut each of the two strands of the double helix at specific points in their sugar-phosphate backbones. Each restriction endonuclease recognises specific palindromic nucleotide sequences in the DNA.
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संबंधित प्रश्न
Rearrange the following in the correct sequence to accomplish an important biological reaction:
(a) In vitro synthesis of copies of DNA of interest
(b) Chemically synthesized oligonucleotides
(c) Enzyme DNA-polymerase
(d) Complementary region of DNA
(e) Genomic DNA template
(f) Nucleotides provided
(g) Primers
(h) Thermostable DNA-polymerase (from Thermus aquaticus)
(i) Denaturation of ds-DNA
Distinguish between RNA and DNA
Write a short note on Electrophoresis.
Give the steps in PCR or polymerase chain reaction with suitable diagrams.
What is gene cloning? Explain different tools used for it.
Following are the four statements regarding separation of DNA fragments using Gel electrophoresis. Identify the INCORRECT statements.
i. DNA is negatively charged molecule and so it is loaded on gel towards the Anode terminal.
ii. DNA fragments travel along the surface of the gel whose concentration does not affect movement of DNA.
iii. Smaller the size of DNA fragment, larger is the distance it travels through it.
iv. Pure DNA can be visualized directly by exposing to UV radiation.
Polymerase Chain Reaction is made possible by ____________.
What is polymerase chain reaction (PCR)?
Give a reason for the following:
DNA cannot enter directly into the host cell.
Study the diagram given below and answer the questions that follow.
- Name the cloning vector shown above. In which organism in this cloning vector inserted?
-
Mention any two restriction sites shown in the diagram.
- Name any two selectable markers shown in the diagram.
