Advertisements
Advertisements
प्रश्न
Name and explain the technique used for separating DNA fragments and making them available for biotechnology experiments.
Name and describe the technique that helps in the separation and isolation of DNA fragments.
Advertisements
उत्तर
Gel electrophoresis is a technique which is used for separating DNA fragments in a gel on the basis of their electric charge and size.
The process of gel electrophoresis is as follows:
-
The fragments obtained after cutting with restriction enzymes are separated by using gel electrophoresis.
-
Electric field is applied to the agarose gel matrix and the negatively-charged DNA fragments move towards the anode.
-
Fragments separate according to their size by the sieving properties of agarose gel. The smaller the fragment, the farther it moves.
-
Staining dyes such as ethidium bromide, upon exposure to UV radiation, are used to visualise the DNA fragments.
-
DNA fragments are visible as bright orange-coloured bands in the agarose matrix.
- These bands are cut from the agarose gel and extracted from the gel piece (elution).
- DNA fragments are purified and used in constructing recombinant DNAs
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
Explain the work carried out by Cohen and Boyer that contributed immensely in biotechnology.
What are plasmids?
One of the major contributions of biotechnology is to develop pest-resistant varieties of cotton plants. Explain how it has been made possible.
Enlist different types of restriction enzymes commonly used in rDNA technology? Write about their role.
What is PCR? Explain different steps involved in it.
From the following which one is NOT a feature of the plasmids?
Vectors are ____________ molecules that carry a foreign gene and replicate inside the host cell.
Which of the following is TRUE regarding EcoR I?
Identify the characters that a cloning vector should possess.
i. Origin of replication (Ori)
ii. Ability to destroy the alien DNA
ii. Cloning site to link the alien DNA
iv. The tumour inducing plasmid Ti
v. Selectable marker
vi. Low molecular weight
From which of the following organisms the enzyme Taq polymerase used in PCR technique is obtained?
Study the following statements regarding separation of DNA using agarose gel electrophoresis.
- Large fragments of DNA molecules move faster than small DNA fragments and thus separate faster.
- DNA being negatively charged migrates to cathode.
In PCR technique, the organism providing thermostable DNA polymerase is a ____________.
Which of the following statements is correct with respect to cellular respiration?
Name the plant disease caused by Agrobacterium tumefaciens.
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'
To be a cloning vector, a plasmid require ______.
Plasmid is ______.
Write steps involved in gene amplification.
______technique is used for in vitro gene cloning or gene multiplication.
