NEET IT: NEET BIOLOGY 360 FOR SURE

  Biotechnology What is Biotechnology? Biotechnology is the use of living organisms and their internal systems for the benefit of the human being. With the advancement of various molecular techniques, scientists have used biotechnology in various fields, e.g. for the production of genetically modified (GM) crop, new drugs, vaccines, enzymes, chemicals for industrial use, diagnosis, to increase the yield of the crop, waste management, etc. Applications of Biotechnology Earlier the use of biotechnology was limited to making bread, alcoholic beverages and cross breed animals and crops. Modern biotechnology makes use of the advancement in science such as genetic engineering and recombinant DNA technology with great effect and has expanded the application of biotechnology for the benefit and well being of humans. 1. Application of Biotechnology in Agriculture The “Green revolution” used the application of pesticides and fertilizers to increase the production of crops. This resulted in exces

  Biotechnology: Principles and Processes Genetic engineering Manipulation and alteration of the genetic makeup of organisms using biotechnology Recombinant DNA (rDNA) is used An organism with a desired trait is generated Bioprocess engineering Use of biotechnology in chemical engineering processes to manufacture products from living organisms in a large quantity E.g. vitamins, vaccines, antibiotics, etc. Plasmid Extrachromosomal, circular DNA, which replicates autonomously E.g. commonly present in bacteria Recombinant DNA (rDNA) DNA formed by combining DNA pieces or desired genes of two different species or organisms Stanley Cohen and Herbert Boyer produced the first artificial rDNA by adding antibiotic-resistant genes to the plasmid of  Salmonella typhimurium Restriction enzymes Molecular scissors, restriction endonucleases They cut the DNA at a specific palindromic sequence forming sticky ends Werner Arber, Hamilton Smith, and Daniel Nathans discovered Hind II – the first restrictio

  How Insulin is produced through Genetic Engineering? Insulin is prepared by recombinant DNA (rDNA) technology for medicinal purposes on a large scale. It was first produced in 1983 by an American Biotech company. The trademark name is Humulin ®  and it is licensed to Eli Lilly, the company which manufactured it for the first time. Genes, which code for functional A and B peptides of insulin, were inserted in the plasmids of non-pathogenic  E.coli  strains. Both the chains are produced separately and joined afterwards by disulphide linkages. Biopharming to produce insulin is being researched. Scientists have succeeded to insert insulin genes in safflower plants. It will help in reducing production cost. Also Read:  What is Plasmid? The Need for Preparing Genetically Engineered Insulin Insulin has been used for many years to treat diabetes. Diabetes is well managed by taking insulin. Earlier insulin was extracted from the pancreas of killed cattle and pigs. It had shortcomings. It used

  What is EcoRI? EcoRI is a restriction enzyme or restriction endonuclease. It cuts the DNA double helix at a specific site. This restriction enzyme was first isolated from  E.coli.  These restriction enzymes derive their names from the organisms where it was first isolated from. Similarly, another restriction enzyme was named HindIII as it was isolated from  Haemophilus influenzae. Here Eco refers to  Escherichia.coli.  R is for the strain RY13 and I (one) as it was the first enzyme to be isolated from the given strain. So EcoRI is pronounced as Eco-R-One. Restriction enzymes present in bacteria are a defence mechanism to protect against bacteriophage. Due to methylation, bacterial DNA remains unaffected. Read on to know more about EcoRI. Key Features of EcoRI EcoRI was discovered in Herbert Boyer’s lab. It is a type II restriction enzyme, which cuts specifically at the restriction site having 5’-GAATTC-3’ sequence. It cuts the DNA at a specific site forming sticky ends. Restriction s

  Ti Plasmid The Tumour inducing or Ti plasmid is present in the bacterium  Agrobacterium tumifaciens. It is widely used now as a cloning vector to deliver desirable genes to the host plant to get  transgenic plants.  The main characteristics of Ti plasmid are: Size of the plasmid is ~ 250kbp There are different kinds of Ti plasmids based on the different genes they possess, which code for different opines, e.g. leucinopine, nopaline, octopine, etc. It is a pathogenic species to many dicotyledonous plants. It causes crown gall disease in plants. It contains one or more T-DNA region Agrobacterium tumifaciens  has an ability to transform the normal cells to tumour cells by inserting a DNA piece known as T DNA and it starts producing chemicals, that are required by the bacterium After inserting the desired gene into Ti plasmid, it loses its pathogenic ability but is still able to insert the desired gene into the plant cell It contains  vir  or virulence genes ,  which transfer T-DNA regio

  pBR322 Plasmid The main characteristics of pBR322 are: Restriction sites:  BamH I, Hind III, Sal I, Pvu I, Pvu II, Pst I, EcoR I, Cla I Selectable marker:  antibiotic resistance genes for ampicillin (amp R ) and tetracycline (tet R ) ORI:  the origin of replication ROP:  It codes for proteins, which are involved in the process of replication of plasmid Different antibiotic resistance genes act as a restriction site and to ligate foreign DNA and for the selection of transformants. The gene, where the foreign DNA is inserted becomes inactive. Alternative selectable marker:  Mostly these have an ability to produce some colour after reacting with a chromogenic substance. The alternative markers are used for the ease of differentiating recombinants from non-recombinants, e.g. gene coding for β-galactosidase. When a foreign gene is inserted between the gene coding for β-galactosidase ,  the recombinant cell does not produce the enzyme β-galactosidase due to inactivation of the gene. In the

  What is Plasmid? Plasmids  are extrachromosomal DNA molecules. They are small, circular and have an ability to replicate autonomously. Replication of plasmid is not under the control of chromosomal DNA. They are mostly found in bacteria. Some of the eukaryotes like yeast and plants also contain plasmids. Their ability to replicate independently makes plasmid a cloning vector in the recombinant DNA technology for transferring and manipulating genes. Many antibiotic-resistant genes in bacteria are present in plasmids. The size of plasmid varies from a few base pairs to thousands of bp. Plasmids also get transferred from one bacterial cell to another by the process of conjugation. Plasmids carrying a specific gene are introduced into bacterial cells, which multiply rapidly and the required DNA fragment is produced in larger quantities. Plasmids are used to prepare a recombinant DNA with the desired gene to transfer genes from one organism to another. This is known as genetic engineering