Genetic Engineering and Biotechnology

The deliberate manipulation or transfer of genes between organisms is the definition of genetic engineering.

The removal and insertion of genes (recombinant DNA technology) is the core process of genetic engineering.

Genetic engineering involves the manipulation of DNA, which includes the hybridization of DNA molecules from different sources.

Genetic engineering aims to add new DNA to an organism to add one or more new favorable traits that are not found in that organism. Genes are the DNA segments that carry the genetic information for the production of particular proteins/ enzymes. These enzymes/proteins determine the traits of an organism, thus alteration in gene structure is the key to impart new traits to the organisms. The genetic information present in genes is copied to the RNA and finally into the proteins; further genes are inherited from generation to generation. Hence, manipulation of RNA, protein or extranuclear gene will be confined to that generation only. Hence, genetic engineering is the manipulation of genes.

• Hirudin is a potent inhibitor of thrombin. Thus, it has a high therapeutic value in the treatment of thrombosis.
  
• Hirudin gene inserted in Brassica napus was synthesized chemically in E. coli and yeast and was found to be a reasonable success. Extended work suggested the production of this protein in a plant system, particularly oil-producing crop.
  

The therapeutic techniques used to treat deleterious phenotypic effects of a genetic defect especially without altering the genetic makeup of the germplasm of the individual is known as Euphenics. Therefore it is the improvement of phenotypic effect in humans after their birth by genetic engineering. Hence option B is correct.

DNA technology, specifically recombinant DNA technology, is the primary method used to introduce desirable changes into the genotype of an organism.

Transgenic mice are being formed for use in testing the safety of before they are used they are used on human beings. They are being used to test the safety of the polio vaccine. The first transgenic cow. Rosie produced human protein enriched milk (2.4 gms per litre). The milk contained the human alphalactalbumin. It is a more balanced product for human babies than natural cow-milk. Bulls with more power are produced by animal breeding not by genetic engineering. So, the correct answer is 'Transgenic mice for testing safety of polio vaccine before use in humans'.

Genetic engineering, also called as genetic modification, is the direct manipulation of an organism's genome using biotechnology. New DNA is inserted in the host genome by first isolating and copying the genetic material of interest using molecular cloning methods to generate a DNA sequence, or by synthesizing the DNA and then inserting this construct into the host organism. Genetic engineering techniques have been applied in numerous fields including research, agriculture, industrial biotechnology, and medicine. Enzymes used in laundry detergent and medicines such as insulin and human growth hormone are now manufactured in GM cells, experimental GM cell lines and GM animals such as mice or zebrafish are being used for research purposes, and genetically modified crops have been commercialized.

Bacteria were the first organisms to be genetically modified. Plasmid DNA containing new genes can be inserted into the bacterial cell and the bacteria will then express those genes. These genes can code for medicines or enzymes that process food and other substrates.

Genetic engineering is possible because all organisms are based on the same genetic code. DNases which act on specific positions or sequences on the DNA are called as restriction endonucleases. The sequences which are recognised by the restriction endonucleases or restriction enzymes (RE) are called as recognition sequences restriction sites. These sequences are palindromic sequences. Different restriction enzymes present in different bacteria can recognize different or same restriction sites but they will cut at two different points within the restriction site. No two restriction enzymes from a single bacterium will cut at the same restriction site. 

Genetic engineering is the process of replicating a specific set of genes from a strand of DNA. It is the process of using gene cloning and other genetic manipulation tools to achieve isolate specific genes. 

There are special techniques for the introduction of recombinant DNA into host cells. Microinjection, biolistics, infection by disarmed pathogens like Agrobacterium or bacteriophage are examples of such techniques.