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12.  Biotechnology and its Applications 

  1. Biotechnology has a wide range application such asbiopharmaceuticals, therapeutics, diagnostics, genetically

  2. modified crops for agriculture, processed food,bioremediation, waste treatment and energy production.

Biotechnology has 3 critical research areas:

  1. Providing the best catalyst in the form of improvedorganism usually a microbe or pure enzyme.

  2. Creating optimal conditions through engineering for acatalyst to act.

  3. Downstream processing technologies to purify theprotein/organic compound.

APPLICATIONS IN AGRICULTURE

  1. Three options for increasing food production

    1. Agro-chemical based agriculture

    2. Organic agriculture

    3. Genetically engineered crop-based agriculture

  2. Genetically Modified Organisms (GMO) or transgenicorganisms are the plants, bacteria, fungi & animals whosegenes are altered by manipulation.

  3. Advantages of genetic modification in plants:

    1. It makes crops more tolerant to abiotic stresses (cold,drought, salt, heat etc).

    2. Pest-resistant crops reduce the use of chemical pesticides.

    3. It helps to reduce post harvest losses.

    4. It increases efficiency of mineral usage by plants (thisprevents early exhaustion of fertility of soil).

    5. It enhances nutritional value of food. E.g. Vitamin ‘A’enriched rice.

    6. GM is used to create tailor-made plants to supply alternative resources to industries, in the form ofstarches, fuels and pharmaceuticals.

  4. Pest Resistant Plants

    1. Pest Resistant Plants act as bio-pesticide.

    2. It reduces the need for insecticides.

    3. E.g. Bt cotton, Bt corn, rice, tomato, potato, soyabean etc.Bt Cotton:

    4. Some strains of Bacillus thuringiensis have proteins that killinsects like coleopterans (beetles) lepidopterans (tobaccobudworm, armyworm) & dipterans (flies, mosquitoes).

    5. B. thuringiensis forms a toxic insecticidal protein (Bttoxin) crystal during a particular phase of their growth. Itdoes not kill the Bacillus as it exists as inactive protoxins.

    6. When an insect ingest the inactive toxin, it is convertedinto active toxin due to the alkaline pH of the gut which solubilise the crystals. The toxin binds to the surface ofmidgut epithelial cells and creates pores. It causes cellswelling and lysis and death of the insect.

    7. Bt toxin genes were isolated from B. thuringiensis andincorporated into crop plants such as cotton.

    8. Most Bt toxins are insect-group specific. The toxin iscoded by a gene named cry. E.g. the proteins encoded by the genes cryIAc and cryIIAb control the cottonbollworms that of cryIAb controls corn borer.

  5. Nematode resistance in tobacco plants:

    1. A nematode Meloidegyne incognitia infects the roots oftobacco plants and causes a great reduction in yield.

    2. RNA interference (RNAi) strategy is used to preventthis infestation.

    3. RNAi is a method of cellular defense in all eukaryotic organisms. It prevents translation of a specific mRNA(silencing) due to a complementary dsRNA molecule.

    4. The source of this complementary RNA is from an infection by RNA viruses or mobile genetic elements(transposons) that replicate via an RNA intermediate.

    5. Using Agrobacterium vectors, nematode-specific genes(DNA) were introduced into the host plant. It producedboth sense & anti-sense RNA in host cells. These twoRNA’s being complementary to each other formed adouble stranded (dsRNA) that initiated RNAi and thus,silenced the specific mRNA of nematode. Thus theparasite cannot survive in a transgenic host expressingspecific interfering RNA.

APPLICATIONS IN MEDICINE​

  1. The recombinant DNA technology helps for the massproduction of safe and more effective therapeutic drugs.

  2. The recombinant therapeutics does not induce unwantedimmunological responses as is common in case of similarproducts isolated from non-human sources.

  3. At present, about 30 recombinant therapeutics have beenapproved for human-use. In India, 12 of these are presently being marketed.

Genetically Engineered Insulin:
  1. Management of adult-onset diabetes is possible by takinginsulin at regular time intervals.

  2. Now, it is possible to produce human insulin using bacteria.

  3. Insulin from the pancreas of animals (cattle & pigs) causesallergy or other types of reactions to the foreign protein.

  4. Insulin consists of two short polypeptide chains (chain A& chain B) that are linked together by disulphide bridges.

  5. In mammals, insulin is synthesized as a pro-hormone.The pro-hormone needs processing before it becomes afully mature and functional hormone.

  6. The pro-hormone contains an extra stretch called the Cpeptide. This is removed during maturation into insulin.

  7. In 1983, Eli Lilly an American company prepared twoDNA sequences corresponding to A & B chains ofhuman insulin and introduced them in plasmids of E. colito produce insulin chains. Chains A & B were producedseparately, extracted and combined by creating disulfidebonds to form human insulin.

Gene Therapy:

  1. It is a method to correct a gene defect diagnosed in achild/embryo. Here, genes are inserted into a person’scells and tissues to treat a hereditary disease. Itcompensates for the non-functional gene.

  2. First clinical gene therapy was given in 1990 to a 4-yearold girl with adenosine deaminase (ADA) deficiency.

  3. The disorder is caused due to the deletion of the gene foradenosine deaminase (the enzyme crucial for theimmune system to function).

  4. This can be cured by bone marrow transplantation or byenzyme replacement therapy (injection of functionalADA). But these approaches are not completely curative.

  5. In gene therapy, lymphocytes from the patient’s bloodare grown in a culture. Then, a functional ADA cDNA(using a retroviral vector) is introduced into theselymphocytes. Then, they are returned to the patient. Thisshould be periodically repeated as these cells are notimmortal. However, if the ADA gene (from marrowcells) is introduced into cells at early embryonic stages, itcould be a permanent cure.

Molecular Diagnosis
  1. Recombinant DNA technology, PCR and Enzyme LinkedImmuno-sorbent Assay (ELISA) are some techniques forearly diagnosis.

  2. Presence of a pathogen is normally suspected only whenthe pathogen has produced a symptom. By this time the concentration of pathogen is already very high in the body.However, very low concentration of a bacteria or virus canbe detected by amplification of their nucleic acid by PCR.

  3. PCR is used to detect HIV in suspected AIDS patients. Itis also used to detect mutations in genes in suspectedcancer patients. It is a powerful technique to identifymany other genetic disorders.

  4. A single stranded DNA or RNA, tagged with aradioactive molecule (probe) is allowed to hybridise to itscomplementary DNA in a clone of cells followed bydetection using autoradiography. The clone having themutated gene will hence not appear on the photographicfilm, because the probe will not have complimentaritywith the mutated gene.

  5. ELISA is based on the principle of antigen-antibodyinteraction. Infection by pathogen can be detected by thepresence of antigens (proteins, glycoproteins, etc.) or bydetecting the antibodies synthesized against the pathogen.

TRANSGENIC ANIMALS

  1. These are the animals whose genome has been altered byintroduction of an extra (foreign) gene by manipulation.E.g. Transgenic rats, rabbits, pigs, sheep, cows and fish.

  2. Over 95% of all existing transgenic animals are mice.Benefits of transgenic animals

  3. To study normal physiology & development:Transgenic animals are used to study how genes areregulated, and how they affect the normal body functionsand its development.E.g. study of complex factors such as insulin-like growthfactor. Genes (from other species) that alter the formationof this factor are introduced and the biological effects arestudied. This gives information about the biological roleof the factor in the body.

  4. To Study the contribution of genes in the developmentof a disease: Transgenic models help for investigation ofnew treatments for human diseases. E.g. transgenic modelsfor many human diseases such as cancer, cystic fibrosis,rheumatoid arthritis and Alzheimer’s.

  5. ​Biological products: Some medicines contain biologicalproducts, but they are often expensive. Transgenicanimals are used to produce useful biological products byintroducing genes which codes for a particular product.E.g. human protein (-1-antitrypsin) used to treatemphysema, products for treatment of phenylketonuria(PKU) and cystic fibrosis etc.In 1997, Rosie (first transgenic cow) produced humanprotein-enriched milk (2.4 gm per litre). It contains thehuman

  6. lactalbumin and is nutritionally more balancedproduct for human babies than natural cow-milk.

  7. Vaccine safety testing: Transgenic mice are used to testthe safety of the polio vaccine. If it is found to bereliable, they can replace the use of monkeys to test thesafety of batches of the vaccine.

  8. Chemical safety testing (toxicity testing): Transgenicanimals are made that carry genes which make themmore sensitive to toxic substances than non-transgenicanimals. They are exposed to the toxic substances and theeffects studied. It gives immediate results.

ETHICAL ISSUEs

  1. Problem of unpredictable results: Genetic modificationmay cause unpredictable results when such organisms areintroduced into the ecosystem.Therefore, Indian Government has set up organizationslike GEAC (Genetic Engineering Approval Committee),which make decisions about the validity of GM researchand the safety of GM-organisms for public services.

  2. Problems of patent: Certain companies have got patentsfor products and technologies that make use of thegenetic materials, plants etc that have been identified,developed and used by farmers and indigenous people ofa specific country. E.g. Basmati rice, herbal medicineslike turmeric, neem etc.

  3. Basmati rice has unique aroma & flavour. India has 27varieties of Basmati. In 1997, an American company gotpatent rights on Basmati rice through the US Patent andTrademark Office. This allowed the company to sell a‘new’ variety of Basmati. This had actually been derivedfrom Indian farmer’s varieties. Indian Basmati wascrossed with semi-dwarf varieties and claimed as anovelty. Other people selling Basmati rice could berestricted by the patent.

  4. Biopiracy: It is the use of bio-resources by multinationalcompanies and other organizations without properauthorization from the countries and people concerned.Most of the industrialized nations are poor in biodiversityand traditional knowledge. The developing and theunderdeveloped world have rich biodiversity andtraditional knowledge related to bio-resources.It has to develop laws to prevent unauthorizedexploitation of bio-resources and traditional knowledge.Indian Parliament has cleared the second amendment ofthe Indian Patents Bill that takes such issues intoconsideration, including patent terms emergencyprovisions and research and development initiative.

REVISION NOTES

 

CLASS 11 BIOLOGY

UNIT I – DIVERSITY IN THE LIVING WORLD

Chapter 1 – The Living World 

Chapter 2 – Biological Classification 

Chapter 3 – Plant Kingdom 

Chapter 4 – Animal Kingdom 

UNIT II – STRUCTURAL ORGANISATION IN PLANTS AND ANIMALS

Chapter 5 – Morphology of Flowering Plants 

Chapter 6 – Anatomy of Flowering Plants 

Chapter 7 – Structural Organisation in Animals 

UNIT III – CELL : STRUCTURE AND FUNCTIONS

 

Chapter 8 – Cell: The Unit of Life 

Chapter 9 – Bio-Molecules 

Chapter 10 – Cell Cycle and Cell Division 

UNIT IV – PLANT PHYSIOLOGY 

Chapter 11 – Transport in Plants 

Chapter 12 – Mineral Nutrition 

Chapter 13 – Photosynthesis in higher plants 

Chapter 14 – Respiration in Plants 

Chapter 15 – Plant Growth and Development 

UNIT V – HUMAN PHYSIOLOGY 

Chapter 16 – Digestion And Absorption 

Chapter 17 – Breathing and Exchange of Gases 

Chapter 18 – Body fluids and circulation 

Chapter 19 – Excretory Products and their Elimination 

Chapter 20 – Locomotion and Movement 

Chapter 21 – Neural Control and Coordination 

Chapter 22 – Chemical Coordination and Integration 

CLASS 12 BIOLOGY

Unit-VI Reproduction
  

Chapter 1 : Reproduction in Organisms 

Chapter 2 : Sexual Reproduction in Flowering Plants 

Chapter 3 : Human Reproduction 

Chapter 4 : Reproductive Health 

Unit-VII Genetics and Evolution

Chapter 5 : Principles of Inheritance and Variation 

Chapter 6 : Molecular Basis of Inheritance 

Chapter 7 : Evolution 

Unit-VIII Biology and Human Welfare

Chapter 8 : Human Health and Disease 

Chapter 9 : Strategies for Enhancement in Food Production 

Chapter 10 : Microbes in Human Welfare 

Unit-IX Biotechnology  

Chapter 11 : Biotechnology Principles and Processes 

Chapter 12 : Biotechnology and its Applications 

Unit-X Ecology and Environment 

Chapter 13 : Organisms and Populations 

Chapter 14 : Ecosystem 

Chapter 15 : Biodiversity and Conservation 

Chapter 16 : Environmental Issues 

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