Question

What is Genetic engineering? How is a beneficial gene amplified through PCR techniques? Explain.

Answer 1

Genetic engineering is the process in which a foreign gene is inserted into the organism. It is brought about by the use of plasmids in which the foreign gene is present. These plasmids are extrachromosomal regions and are circular.

Complete answer:
Genetic engineering is techniques after the chemistry of genetic material (DNA and RNA) of introducing these into host organisms and thus changing the phenotype of the host organism. It involves modification and amplification of the desired gene that has been corrected. The amplification of the genes is carried out by PCR techniques. This enables the production of the desired gene/product on a large scale. It is used in producing antibodies, hormones, etc. The process of incorporating foreign genes is shown with the help of the diagram below.

PCR amplification Basically, PCR is DNA replication on a grander scale. The polymerase chain reaction takes place in the following steps
1. Denaturing: the starting solution is heated, usually to 940C. The high temperature breaks hydrogen bonds between the two strands of the original DNA double helix, Providing the necessary single-stranded template.
2. Annealing: after just a couple of minutes at the temperature, the reaction mixture is quickly cooled, usually to somewhere between 50 and 600c. It is then held for less than a minute at the lower temperature – which is enough time for the primers to bind to their complementary sequence on the single-stranded template.
3. Primer extension: This is also called polymerisation. The sample is next heated to 720c for some time, during which time the DNA polymerase adds nucleotides to the primer, synthesizing a new DNA strand using only the temperate sequences that bind the rimer.

Note: If the process of replication of DNA is repeated many times, the segment of DNA can be amplified to approximately a billion times, that is 1 billion copies are made at the end of the PCR cycle. It is possible to generate “2n” molecules after the “n” number of cycles