CBSE Class 10 Science Biotechnology Notes

BIOTECHNOLOGY

INTRODUCTION

Biotechnology is these of living substances or of substances obtained form them in industrial processes. By the controlled utilization of biotic entities like animals, plant cells and their components or microorganisms, several useful products for man have been manufactured with the help of biotechnology.

OBJECTIVES OF BIOTECHNOLOGY

1. Production of such products whose availability is inadequate or not available.
2. Development of new techniques to minimize the cost of industrial processes.
3. Production of safe and high quality products.
4. The main objective of biotechnology is to exploit the resources judiciously for the welfare of human society.
5. The traditional use of plants and animals is not included in biotechnology like agriculture, horticulture and animal husbandry are already in existence for such aspects.

HISTORY

1. The term biotechnology was coined by a Hungarian Engineer Kari Ereky in 1901.
2. It became well established as a branch of science oat the end of twentieth century.
3. The structure of DNA molecule was given by Watson and Crick (1953)
4. Werner Arber (1971) discovered a specific enzyme called restriction enzymen form bacteria. This enzyme can cut the DNA thread at appropriate point.
5. In 1973 S. Cohen and H. Boyer extracted a specific gene form a bacterium and inserted it into another bacterium with the help of restriction enzyme. It helped the beginning of recombinant DNA technology.
6. This technology is the basis of genetic engineering. With the help of recombinant DNA technology and desired gene form any organism can be removed and further it can be transferred or inserted into another organism.
7. The gene transferred by this technique is called transgene and the organism in which transgene is transferred is called transgenic organism.
8. In 1976 Baltimore and Baltimore transferred a growth hormone gene of man into rabbit.
9. In 1997 Dr. Ian Wilmut of  Roslin Institute of Edingberg-Scottland successfully developed a clone of sheep, the
10. ‘Dolly’. In 1979 human growth hormone was synthesised.In 1980 Paul Berg, Fredric, Sanger’ and associates were awarded Nobel prize of the discovery of recombinant DNA. The production technology based on genetic engineering is often called Modern Biotechnology.

INTERRELATION OF BIOTECHNOLOGY WITH OTHER BRANCHES OF SCIENCE:

BIOTECHNOLOGY GENERELA INFORMATION

1. ANTIGEN : A compound which induces the formation of antibody
2. Cellus :
3. Wound tissue formed ion a wound.
4. An undifferentiated mass of cells formed during the plant tissue culture.
5. DNA Ligase : Enzyme which joins the DNA fragments.
6. DNA : The hereditary substance present in nucleus which controls the various metabolic activites alontg with the transmission of characters form generation to generation.
7. Recombinant DNA : The altered DNA, formed by manipulation in the original DNS constitution of an organism using artificial methods in laboratory, is known as recombinant DNS.
8. Recombinant DNA technology – It includes those methods by which recombinant DNA is prepared. The methods like incision of DNS segments, reunion of segments by enzymes and fusion of these segments with NA of other organisms are included under recombinant DNA technology.Genetic engineering : Beneficial changes in the heredity of an organism by genetic manipulation.
9. Plasmid : An extrachromosomal circular DNA present in some bacteria.
10. Restriction endonuclease : An enzyme that catalyses the cleavage of DNA at a highly specific. Site.
11. Vector : An agent (structures) used to transfer DNA from one organism to another organism.
12. Cloning : A process by which large number of identical copies or clones of a DNA or gene are developed.
13. Explant : The plant part from original source for the initiation of tissue culture on culture medium.
14. Interferon : An antiviral pertinacious agent synthesized by a tissue when attacked bya virus known as interferon.
15. Bacterophage : Viruses which infect bacteria.
16. Nif gene : Genes responsible for nitrogen fixation.
17. Culture : Microorganisms grown or cultured on culture medium.
18. Red biotechnology : Medical application of biotechnology.
19. Green biotechnology : Application of biotechnology in the field of agriculture.

BIOPATENT :

The security of rights of personal property are guided by the laws prevailing in the country. In the present times domination of knowledge based societies is increasing India is at position one in the queue of the knowledge based societies. The main basis of financial strength of such societies is creation and preservation of intellectual assets by them.

Intellectual property can be in the form of a design, a concept, an idea, a research or any symbol. This property should be recognized as a personal or individual property since its various forms are the result of mental capabilities of individual concern. For the security and recognition of intellectual assets, their protection by legal provisions necessary. The legal production provided by the government to these things is called patent. The exclusive right granted by a government to an inventor for a limited period of time to prevent others from commercial use of his invention including a product or a design.

Patents related to organisms and their components are called biopatents. In other words biopatents are granted for biological entities and the products derived form them. Biopatents are granted for the following.

(i)  Strains of microorganisms,    (ii) Cell lines,

(iii) Genetically modified plants and animals, (iv) DNA sequences

(v) The proteins encoded by DNA sequences,  (vi)  Various biotechnical processes.

(vii) Production processes  (viii) Products and

(ix) Application of pr4odicts.

In India the validity of a patents is for 20 years. The patent act made effective in India on April 20, 1972.

BIOTECHICS :

Ethics includes a set of standards and norms by which a person or community regalities its behavior and decides as to which activity should be done or not. Therefore, bioethics can be considered as a group of norms and standards, on the basis of which our behavior and vision toward the b biological worlds can be regulated. In biotechnology, particularly recombinant DNA technology is centralized over the exploitation of biological world by various methods. 

PLANT TISSUE CULTURE :

The growth and maintenance of paint cells, tissues and   organs on a suitable culture medium in vitro (in a container, e.g. test tube) is called plant tissue culture.

A plant cell, tissue or organ excised form its original source and cultured in vitro is called explants.

Tissue culture is of the following main types :

(i)   Plant culture - Culture of seedling.

(ii)  Embryo culture - Culture of isolated embryo.

(iii) Organ culture - Culture of cells or tissues.

(iv) Tissue culture - Culture of isolated protoplast.

(v) Protoplast culture - Culture of isolated protoplast. 

TYPES OF PLANT TISSUE CULTURE :

The types of plant tissue culture are mainly based on the type of growth (e.g., callus or suspension culture) or the type of the explants form which the culture is initiated e.g., embryo, anther sac, protoplast culture.

(a) Callus Culture :

Callus is an unorganized group of cultured cells. It is grown on agar culture medium. Agar is a jelly like substance obtained form sea weeds (algae). Substances like auxins (2.4 dichlorophenoxyacetic acid 2,4-D) and cytokinins (Benzyl amino purine - BAP) are commonly present in culture medium. When the explant is kept in culture medium its cells begin to divide and an unorganized mass of cells or callus is formed within 2-3 weeks.

Suspension Culture : In suspension culture solitary cells or small group of cells are maintained suspended in the liquid culture medium. The explants is kept in liquid medium. The suspension cultures are necessarily agitated continuously by electrically driven agitaters at the rate of 100-200 revolutions per minute, so that the culture medium is continuously inter mingled and the group of cells keep on braking into small groups. The growth rate of suspension cultures is fairly high as compared to callus cultures.

The callus and suspension. cultures are used for the production of biochemical, transgenic plants, protoplasts and regeneration.

Types of explants

Use of callus and suspension culture

(b) Regeneration of Plantlets :

The cells cultured in invitro culture finally give rise to a complete plants. Such a characteristic of plant cells is known as totpotency. During regeneration the cultured cells from definite structures like shoot and root. BAP (Cytokinin) Stimulates shoot regeneration whereas N”AA (Naphthalene acetic acid-an auxin) is responsible for the production of roots. Infect formation of shoot and roots is controlled by balanced activity of auxin and cytokinin. The embryo formed by somatic cells is called somatic embryo.

(c) Establishment of Plantlets into Field :

The plantlets from culture containers are shifted and planted into fields. It is done by a process known as hardening. During hardening the plantlets before establishing in field are fist put under re3duced light and high humidity for sometime to make them hard and acclimatized to the atmosphere.

PROTOPLAST CULTURE AND SOMATIC HYBRAIDISTATON :

The hybrid formed by the fusion of somatic cells of different varieties or species is call somatic hybrid. The process of their formation is called somatic hybridization. The various steps of this method are

(i) First of all the cell wall of the plant cells is dissolved by the help of enzymes like pectinase and cellulose. After dissolution of cell wall the remaining of the cell is known as protoplast.

(ii) The fusion between protoplast of selected par3ents is called protoplast fusion. It requires a treatment by a solution of polyethylene glycol (PEG) or by a very brief high voltage electric current.

(iii) The product of fused  protoplasts is cultured in suitable medium, First of all the cell wall is regeneration followed b y division of the cells and  finally the generated of plantles take place. The plantles are subsequently established in the field after proper hardening.

(a) Importance of Somatic Hybridization :

Somatic hybridization provides an opportunity for the production of hybrids. Somatic hybrids can be used for the transfer of genes and cytoplasm.

DEVELOPMENT OF NEW PLANT VARIETIES :

The process of development of new varieties of plants is a long and highly complicated. For the development of high yielding varieties following important stepes are involved.

(a) Generation of Genetic Variation :

Change in the genotype of plants is known as genetic variation. It can be achieved by the following methods –

(i) Collection of germ plasm : The total number of genes present in a crop and related species is known as germ plasm of that crop. Germ plasm is that matter by which improved verities can be developed. Therefore for successful breeding a collection of useful germ plasm is necessary. The collection of germ plasm is done from various parts of the country and even form other  countries.

Use of somatic hybrid

(ii)  Mutation : Sudden and inderitable change in the characters of organism is called mutation.  It can take place by change in the structure of chromosome and change in the number of the chromosome. The factor or agents which induce mutation are called mutagens.

Mutagens are two type : Chemical mutagens e.g Ethylethane sulphonate (EMS) and sodium

Azide and  Pysical mutagens e.g.alpha  gamma and ultraviolet radiations.

(iii) Hybridization: it is most commonly used method for creating genetic variation. A cross between populations or parents of different of different genotype is called hybridization

(iv) Polyploidy. The plants are eukaryotic which are commonly dipoid or polploid. A condition when a somatic cell contains more the two sates of genomes is know as polypoidy

(b) Selection : Selection of plants with superior and desired characters and development the next generation b their seeds is called Selection. By selection, characters of crop can be improved.

(c) Evalution : A newly developed population and hybrids with regard to their quality and disease and insect resistance is thorohgly evaluated. In India, it is done by ICAR  ( Indian Conucil of Agriculture Research)  New Delhi

(d) Multiplication of improved seeds : Increase in number of seeds of new varieties is called multiplication. Multiplication makes it possible to distribute the seeds of the improved varieties to the farmers. In plant breeding the meaning of seed is that part of the plant by which new crop is grown. The grains of wheat and paddy. Tubers of potato and stem cutting of sugarcane are called seeds only in the case when used to new crop.

(e) Distribution of Improved Seeds

Seeds of superior quality are called improved seeds. So they are distributed to farmers and agriculture research stations.

PRODUTION OF FOOD FROM SEA PLANTES :

In oceans algae can occur on rocks, coral rocks and free floating and commonly in photic zone. The edible sea algae are also called vegetable. Marine algae are rich in magnesium, iron, calcium, vitamin B (folate. Riboflavin, panthothenic acid) and anticancerous lignin

Kelp : a marine is alga is the richest source of iodine containing highest amount of the element in nature. Preasntly janan is the largest consumer of sea algae as food. It is also the top most producer and exporter of edible sea algal. The commonly used are follow.

(i) Nori  : Porphyra sp.

(ii) Kombu :  Laminaria sp.

(iii) Kelp.  : Undaria pinnatifida

(vi) Irish moss : Chondrus cryspus

Sea algaea are good source of protein. For example  Nori contains 25 – 33% proteins of its dry weight, 17.5 time more vitamin C than orange and also rich in iodine. 

MEDICAL BIOTECHNOLOGY :   

(a) Introduction :

Food and health occupy a prime position human efforts alongwith scientific development. There is no doubt, that because of this reason only, there has been maximum research in the filed of medicine and health.  Many aspects of prevention, diagnosis and cure related to various disorders and complex human health problems, are being dealt conveninety biotechnolory is increasing in reference to following medical fileds –

(i) Informatious diseases

(ii)  Matabolic and homeostatic imbalance

(iii) Herediary diseases

(iv)  Treatmant of Tumours & cancer

In medical field, biotechnology has been used in

(i) Synthesis of new effective antibiotic.

(ii) Synthesis of low cost steroid medicines and hormones –

(iii)Development of better & safe vaccines

(iv) Decreasing the use of chemicals in the treatment of diseases

(v) Better use of radioactive substance. s

The latest service of biotechnology in medical filed is stem cell research. This stem sell research is the main basis  of tissue culture, organ culture and cloning

STEM CELL. 

‘Zygote’ gives rise to the complete is individual. that this single cell, contains the complete information about the development of the whole body. This cell has the capability of developing into any other kind of body cell, by undergoing division differentiation. 

1. The cells, which are the basis of development of a particular group or tissues, in an adult organism or during its embryonic development, are called stem cells.
2. Blood cellar are formed from the stem cells situated in bone marrow, called the Haemopoietic cells.
3. The stem cells which have the capability of developing into any other kind of body cell are called as Totipotent cell e.g. blastomeres.
4. While the cells, which are capable of developing into a few special of calls are called pleuripotent.e.h. haemopoietic cells.

CLONING :

1. Clone is a Creek work which means branch
2. Clone is a copy or a duplicate, obtained by asexual reproduction from a parent (mother or father) which cannot be considered as their offspring. This process of formation of a close is called as coning.
3. Stem cell research in the main basis of cloning technique
4. Cloning is the process of development of a group of cells, tissue, organ or a complete individual by division and differentiation of single cell.

All the cells obtained as , a product of this process of have same genetic constitution. These cells are exact  replicas (copies) of each other and they are called as clone.

(i) Adult DNA cloning or complete organism cloning  : It is attempt of produce duplicates of an organism  through this process.

(ii) Embryo cloning  : This is process of development of  Monozygotic twins or triplets.

(iii) Biomedical cloning : In this process, totipotent cells are separated from blastua or its earlier stage and are used for culturing type of tissue or organs which can be transplanted again in the person. 

(a) Animal Cloning :

Sheep “ Dolly” was a clone, cloning is a method of producing many identical organisms. Dolly was produced from a single of her mother, it had no father. Its hereditary characters were exactly like its mother because it was an offspring of a single parent. Dr. la Wilmut of Scotland produced the first mammalian clone sheep named Dolly in 1997

Plants or Animals normally reproduce by sexual method but clones can be produced from a single animal or plant. An egg cell is taken from a female and its nucleus is removed (enucleated). A nucleus taken out from a somatic cell of some other mother, it develops it develops into a new organism. Cell cloning is possible because of the presence of totipotency in plants and pleuripotecy of animals.

· Many laboratories of Department of Biotechnology of Government of india re working in this filed. Some other main organizations are – National institute of immunology, New Delhi and Central for Cellular and Molecular Biology. Hyderabad etc.

(b) Microbial Cloning :

A genetically transformed microbial cell produced as many duplicate copies (replieas) as may times it divides. In a few days. It produces thousands of clone cells each containing the same original genotype. In Biotechnology many improved genetically transformed micro – organisms can be obtained in large numbers by cloning. The micro – organisms transformed by genetic engineering can be used for various purposes.

e.g. E. oil is helpful is production of Human Insulin. Human growth factors and Interferons. While bacteria Rhizobium meliloti is helpful in incorporating “nif” gaen for nitrogen fixation in crops. 

(c) Plant Cloning  :

Many drought resistant, insect resistant and herbicide toleratnt crops have been produced by gene manipulation for agriculture. Food produced b gene manipulation, in which desired characters have been incorporated is called genetically modified food. Many genetically modified food material e.g. lysine – rich pulses and vitamin –A – rich rice, are becoming important constituents of human food. Animal cloning is more difficult as compared to plant cloning

BIOMEDICAL CLONING :

(a) Tissue Culture :

Tissue culture is a technique in which tissue or cell. is separated from the body  of the organism. Ross Harrison (1970) started work in the field of tissue culture and organ culture of organisms. They used frogs tissues as a source because they have high power of regeneration and grow fater as compared to mammalian tissues.  Tissue culture has a significant contribution in cancer research and production of antiviral vaccine.

 (b) Organ Culture :

1. Part of an organ or its, process can be grown in artificial culture medium but it has not been possible to culture a complete organ as yet. Lot of care has to be taken during culture so that the tissue does not get damaged curing the process
2. Embryonic organs can be cultured easily but the process of culture of adult organs is very complex and difficult. Special type of Serum- free media and special culture chambers are required for adult organ culture. The embryonic organs can be cultured in be culture in a two way (i) in Liquid medium (ii) in Solid medium

(c) Implantation of Cultured Organs :

The most important aspect in the technique of implantation of cultured organs is theat there shold be similarity in the genotype of the donor and the recipients. More the similarity in the genotype, higher will be the success rate of organ transplantation.

In transplantation, the normal response of the recipient is to reject the external factors because of the presence of many antigens in them. At the time of organ transplantation, the immune system of the recipient may consider it as foreign body and may reject it and destroy the transplanted organ. Therefore, immunosuppressant medicines are used so that the immune system may7 not give any repose against the transplanted organs.

The success of the organ transplantation depends completely on the histocompatibility antigens present in the body cells.

TEST TUBE BABY

Test tube baby is the main achievement of biotechnology in human welfare. In this technique, the ovum is obtained form the body of the female and is fertilized by the sperm of the male, under controlled conditions. Thsii whole process is compaleted outside the body of the female, in the laboratory. If the egg cell or ovum is correctly fertilized and the process of cleavage starts in the fertilized eff. Then it is transplanted into the uterus of the female, where  it undergoes normal development. Test tube baby is a baby obtained by normal development in uterus of the female but after in-vitro fertilization in the lab. The fist test tube baby of the World, Louise Hoy Brown was born on 25^th July, 1978 in Britain. The fist test tube baby of India “Harsha” was born in 1986.

ARTIFICALL INSEMNATION :

Artificial insemination is a process of biotechnology. Collecting the semen of male animals, storing it at extremely low temperature in suitable medium and transferring it into the vagina of an oestrous female of fertilization is called artificial insemination. The main aim of artificial insemination is quick improvement in the breeds of animals.

(a) Methods of Artificial Insemination :

The main steps of artificial insemination are as follows :

(i) Collection of Semen :  The semen of males of high quality breeds of animals is collected by different methods.

(ii) Examination of Semen : The semen of males of high quality breeds of animals is collected by different for the number of sperms, their viability in the vagina of female and their capability of fusion with the ovum.

(iii) Semen preservation : for preservation the semen diluted so that its volume is increased and iut5 can be preserved for a long time. The substances which make the semen diluted, are called dilatants or diluting factors. Main diluting factors are egg yolk phosphate (phosphovitellin) and egg-yolk glycine. The preserved semen  can be transported form one place to another. The dilated semen is preserve at – 196⁰ C (low temp.) in liquid nitrogen.

(iv) Insemination in female animal : The semen is introduced in the vaginal of the female  (when in “heat”) by rectovaginal technique or any other method. It is important that all the instruments and equipments used in artificial insemination should be properly sterilized or disinfected.

(b) Importance of Artificial Insemination :

It has following advantages :

(i) The improved varieties or superior breeds of the animals can be produced by this method but possibility of such production is very little by natural reproduction.

(ii)  The cattle farmers need to keep a few males so that they get maximum advantage in maximum expenditure.

(iii) Artificial insemination increases the capability of females to become pregnant.

(iv) It provides superior breeds of cows which give more milk and sheep producing high quality wool.

(v)  High quality off springs can be obtained by fertilizing a large number of females, even if the number of superior males is less. 

(c) Difficulties or Problems in Artificial insemination :

(i) Trained cattle farmers are required for the process, who are not available at many places.

(ii) All equipments or instruments must be sterilized and should be of very high quality, which is very expensive.

The expertise of identifying a female on “heat” comes by hard work and long-experience. 

USE OF RADIOACTIVE ELEM,ENTS IN MEDICAL SCIENCE :

The slements which have same number of protons but have different number of neutrons are called isotopes. Such type of atoms emit many types of radiations and are called as radioactive isotopes.

These elements emit alpha (α), beta (β), gama (γ) rays alongwith X-rays and neutrons.

APPLICATION OF X-RAYS IN MEDICAL SCIENCE :

X-rays are actually elector-magnetic rays. They are invisible and do not create any sensation in the person when they pass through the body. Image of internal part of the body can be obtained by X-rays specially bones, jaws, teeth, kidney, lungs etc. At present X-rays are used in techniques like X-Ray imaging, C.T. Scan (or computerized tomography) and fluoroscopy etc. The image of transverse section of any part of the body can be obtained by using C.T. Scan technique. 

CANCER RADIOTHERAPY

Radioactive substances are also used in cancer treatment. The cells of the tumour are more sensitive to the radiations as compared to normal cells. That is why radioactive substances are highly effective in controlling the tumour cells. In cancer treatment, radioactive substances are manly used as follows.

(a) Palliative Theraphy :

The main aim of this treatment is, to provide relief form pain to the patients, in terminal stages of cancer.

(b) Curative Therapy :

The main aim of this therapy is tumour control and its destruction. In palliative therapy, radiations are given in mild does, so that they do not cause any side effects alongwith analgesic effect. But in curative therapy, radiations are given in very high dose. That is why they result in many side effects-specially hair loss.

(c) Brachytherapy :

Brachytherapy is another type  of radiotherapy, in which radioactive a substance is implanted in the tumour Itself e.g., external tumour of neck and head; tumour of prostrate gland etc.

USE OF LASER RAYS :

The laser rays (Light Amplification by Stimulated emission of Radiations) are used in microsurgery in medical field, the effect of laser on tissues, depends upon their wavelength. It depends upon the type of laser rays.

1. The wavelength of light produced by carbon dioxide laser is 10.16 µm which absorbs the water form the target cells and its energy is very quickly converted into heat. As a result, the effect of laser light is highly localised.In neurosurgery, laser rays are used in destroying those brain tumours,  which can not be easily removed by surgery.
2. Visual argon-ion laser have moderate effect on the tissues so they are used in the microsurgery of eyes.
3. The diseased tissue of the body can be removed by laser rays. There is no loss of blood in this surgery, not tearing of tissues and no anaesthetic drug is given to the patient, this is also called as Bloodless surgery.
4. Holium laser technique has made it easy to get rid of any type of urinary disorder without surgical operations.

RECOMBINANT TECHNOLOGY :

Biotechnology is the science of application of manipulate DNA in the field of human welfare. This definition underlines the importance of genetics in biotechnology.

1. The development and application of manipulated DNS is called genetic engineering.
2. DNA is the genetic material in all the organisms.
3. In recombinant technology the DNA molecule is manipulated by, changing the nucleotide sequence, joining the different nucleotide sequences. Transfer and establishment of changed sequence into a suitable organism. The important outcome products of the above applications are -

(i) Recombinant DNA : When two DNA form different sources are united or combined, the resultant DNA is called recombinant DNA

(ii) Transgenic organism : When genes of different species are transferred into an organism, the newly formed hybrid is called a transgenic organism. It shows all the characters of the transferred genes.

(iii) Gene therapy : It is possible to change the genotype or genetic constitution of a cell or organism by the application of biotechnology. By doing so, the genetic diseases can be treated effectively.

(a) Recombinant DNA Technology :

A technique which provides an opportunity of integration the genes or DNA of two different organisms into one is known as recombinant. DNA technology. The organisms which contain genes of other organisms inaddition are called genetically modified organisms (GMO) or transgenic organisms.

The technique  of recombinant DNA  technology can be employed for the transfer of genes responsible of the synthesis of insulin, growth hormones, a - interferon, factor VIII (antihemophilic factor) into other organisms particularly into bacteria.

APPLICATION OF RECOMBINANT TECHNOLLOGY :

(a) Production f Insulin form Bacteria :

When the b - cell of pancreas fail to synthesize adequate amount of insulin, the person is said to be suffered form Diabetes mellitus.

Human insulin is obtained form a bacterium Escherichia coli. The genes responsible for the synthesis of insulin have been incorporated into E coli for this purpose. It is called humulin.

For the production of a transgenic plant the desired genes with the help of a suitable vector or carrier are transferred and integrated into a new planet cell. Ti plasmids are largely employed as a vector for the production of transgenic plants.

Bt plant : This transgenic plant has been produced by introducing a genes of a bacterium Bacillus thuringiensis into it which is responsible for the synthesis of a toxin that can kill the caterpillars of the insects. Recently Bt gene has been successfully incorporated in maize, cotton and soyabean.

(c) Transgenic Animals :

A transgenic animal in which a gene of other species or source is incorporated. The foreign gene is incorporated in the embryo of the animal. The transgenic remains active in embryo or it can modify the expression of other gene. Transgenic animals are produced due to the following advantages.

(i) Development of economically advantageous animals : In some milk giving cattles, human genes controlling the synthesis of human proteins have been incorporated.

(ii) Development of disease model :  The transgenic animals are highly suitable for the better understanding of several diseases of human beings. It helps in the treatment of the disease. e.g. various carcinogenic genes were transferred into transgenic rates-Onco mouse to understand the development of cancer in man.

The transfer of foreign gene into the embryo of transgenic animal is done by sophisticated techniques like DNA microinjection, embryonic stem cell – mediated gene transfer etc.

GENE THERAPY :

Many disease in human are of hereditary nature e.g. hemophilia. Some diseases are caused by mutation of genes. Such diseases are not cured by general treatment methods. Hereditary diseases can be completely cured by changing the genetic composition. Gene therapy include replacement or al alteration of defected gene, substitution of normal gene in place of a defected gene and inhibition of the activity of the defected gene etc. In the recent times treatment f some hereditary diseases like heamophilia, thalassaemia, cystic fibrosis, certain categories of cancer, high blood pressure and muscular distropy etc. is possible by ge3n therapy.

(a) Gene Therapy of Hemophilia :

Hemophilia is a genetic disorder in which the blood coagulating factors like factors VIII, IX are lacking. The patient cannot sustain even a small injury. The flow of blood form the wound continues and ray cause death of the injured. Gene therapy can introduce the genes responsible for the production of factor VIII and IX in the cells of the patient andIXinthecellsofthepatient.