hi guyes!!!!!
lets discuss about genetic engineering and its role..  but first we will discuss about recombinent DNA technology

Recombinant DNA

“Recombinant DNA is a form of DNA which is constructed in laboratory”. It is generated by taking a piece of DNA from an organism. Recombinant DNA is used for many different purposes in research, for the production of medicines, in industries and many more. Recombinant DNA is an artificial form of DNA because that DNA does not exist in naturally in an organism so it is synthesized in laboratory by the joining of genes that would be taken from different sources (donor organism and vector ).This process is done by selecting a gene of interest from an donor organism. Before the use of Recombinant DNA Technology general methods were used to isolate a DNA from donor. Bulk of DNA extracted is taken out that will be genomic DNA Eukaryotes or genomic DNA Prokaryotes.

After that isolation ,cutting the gene from DNA at a specific point with the help of Restriction Restriction Endonucleases enzyme act as a Molecular scissors. Restriction enzyme are produced by the bacteria for their defence from phages .Restriction enzyme is important in suitable DNA manipulatoin. DNA is inserted into a circular piece of bacterial DNA(plasmid) or on a bacterial virus (phage).

Mostly bacterial plasmid is used as vector They are small ,usually carry only one gene or a few genes plasmid are circular, and have a single origin of replication. Plasmid DNA is denser then chromosomal DNA. Plasmid is carry genes for resistance to the antibiotic (Tetracycline and Amphiciline). Tetracycline is used to separate the plasmid DNA from the bacterial chromosomal DNA.

By the use of same restriction enzyme plasmid and host DNA cuts and form the sticky ends of same shape. The principle is that if two different DNA molecules are cut with the same restriction enzyme both fragments with the same complementary sticky ends comes, it is possible for DNA chimeras(plasmid contain other organism DNA). The gene of interest is joined with the sticky ends with the help of another enzyme DNA ligase, which ligeted plasmid with host DNA. Recombinant DNA is then interduced in to the bacterial cell by the process of transformation .After that it is inserted in a host organism .where plasmid vector able to replicate .The resulting colony of bacteria will contain billions of copies .