Chapter 12: Biotechnology and Its Applications

ADA (i.e., adenosine deaminase) deficiency is a genetic disorder caused by the deletion of a gene for adenosine deaminase synthesis which leads to the deficiency of the ADA enzyme in the body, which causes damage to the immune system. It can be cured by bone marrow transplantation or enzyme replacement therapy. These do not cure the deficiency completely. Another approach is like growing lymphocytes outside the body of the patient in cell culture and using a functional ADA complementary DNA (i.e., cDNA) in those lymphocytes. If this procedure is done at an embryonic stage, then it can be cured permanently.

Transgenic animals are animals which are genetically modified for various purposes. By using the recombinant DNA technology, a foreign gene named ‘Transgene’ is inserted into the target organism to bring modifications in their gene expression.

1. Biological studies:

2. Increases the yield product

3. Testing and clinical trials

4. Diseases study and chemical safety testing

Step 1 Isolation of useful gene by using restriction endonuclease enzymes

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Step 2: Transferring the isolated gene to a suitable vector to create a recombinant DNA molecule

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Step 3: Transfering the recombinant DNA molecule into the target cell

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Step 4: Screening of cells for obtaining the transformed cells and discarding the untransformed cell.

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Step 5: Selection of the required transformed cell

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Step 6: Regeneration of the plants from the transformed cells to get a transgenic plant.

The five areas where biotechnology has influenced our lives are:

1. Therapeutics and Diagnostic tool: There are methods which treat adenosine deaminase deficiency, and rDNA technology is used for the production of Insulin and Human Growth Hormone (HGH). PCR (i.e., Polymerase Chain Reaction) is widely used as a diagnostic tool for disease detection and methods like gene therapy are used.

2. Genetically modified plants and animals: Transgenic animals are one of the kinds of modified organisms which is used to get more products like milk from cows, wool from sheep etc.

3. Forensic and paternity tests: Biotechnological methods like DNA fingerprinting have helped in solving crime cases and the determination of genetic parents.

4. Wastewater treatment: Micro-organisms are added to the wastewater, which is digested by the bacteria, and it helps in the degradation of organic waste.

5. Energy production: Biotechnology is used for the production of energy through micro-organisms and producing biofuel.

1. Genetically modified plants are more resistant towards abiotic stresses like climate, temperature and pH changes. Thus, the plants can grow normally in unfavourable conditions.

2. Genetically modified plants can give more yields of products.

3. Genetically modified plants are more resistant towards pests and insects

4. Genetically modified plants are used for growing crops with higher nutritional values in starch, proteins, vitamins, etc.

5. Genetically modified plants have products i.e., fruits or vegetables, with a much longer shelf life.

(a) A nematode, Meloidogyne incognita, is known to cause root rot in the tobacco plant. Initially, nematocides were used to deal with this nematode. The RNA interference (RNAi) method was developed by scientists to kill the nematode by modifying the tobacco crop. Scientists introduced a host-specific double standard DNA using Agrobacterium tumefaciens.

(b) Golden rice is the transgenic variety of basmati rice which gives high yield and is rich in vitamin A, a β-carotene gene from the daffodil plant that was introduced into the rice plant to nutritionally enrich with vitamin A

1. The insulin obtained from slaughtered animals was slightly different from humulin and caused allergic reactions in humans

2. Slaughtering animals for insulin is against ethics.

3. Cost of bovine insulin was very high.

1. Recombinant insulin had no allergic reactions, while bovine-caused allergy.

2. This stopped slaughtered of a large number of animals

Bio-pesticides are biologically present substances which are used to control pests.

These are narrow-spectrum & species-specific. e.g. – Bt toxin, which is obtained from Bacillus thuringiensis, is used against insects. Insects, when ingesting Bt toxin, due to the presence of its alkaline nature, Bt toxin gets activated and binds to the gut wall, and creates pores hence the insects die.

a) Restriction endonuclease – It cuts the DNA sequence at specific positions.

b) Vector – It is the most important tool for the rDNA technology vector contains a site for the insertion of the gene of interest called the origin of replication.

c) DNA ligase – It facilitates the joining of desired DNA with vector DNA

d) Polymerase – The enzyme makes multiple copies of rDNA.

e) Host cell – The cell which takes up rDNA & changes itself to transformant.

When Biology is used to develop solutions and technologies to improve the lives of human beings, this technology is called Biotechnology. The field of Biotechnology has many different uses, particularly in the modern day. Its applications are quite varied and have a close link with various fields such as energy production, GMOs, food processing and waste management.