Chapter 12: Biotechnology Solution [ Exercise,Solutions,Notes ]

Biotechnology Solution [ Exercise,Solutions,Notes ]

Choose the correct option

Exercise | Q 1.1 | Page 291

The bacterium which causes a plant disease called crown gall is _______________.

Helicobacter pylori

Agrobacterium tumifaciens

Thermophilus aquaticus

Bacillus thuringienesis

Solution:

The bacterium which causes a plant disease called crown gall is Agrobacterium tumifaciens.

Exercise | Q 1.2 | Page 291

The enzyme nuclease hydrolyses _____________ of polynucleotide chain of DNA.

hydrogen bonds

phosphodiester bonds

glycosidic bonds

peptide bonds

Solution:

The enzyme nuclease hydrolyses phosphodiester bonds of the polynucleotide chain of DNA.

Exercise | Q 1.3 | Page 291

In vitro amplification of DNA or RNA segment is known as ___________.

chromatography

Southern blotting

polymerase chain reaction

gel electrophoresis

Solution:

In vitro amplification of DNA or RNA segment is known as the polymerase chain reaction.

Exercise | Q 1.4 | Page 291

Which of the following is the correct recognition sequence of restriction enzyme hind III?

5'---A-A-G-C-T-T---3'

3'---T-T-C-G-A-A---5'

5'---G-A-A-T-T-C---3'

3'---C-T-T-A-A-G---5'

5'---C-G-A-T-T-C---3'

3'---G-C-T-A-A-G---5'

5'---G-G-C-C---3'

3'---C-C-G-G---5'

Solution:

5'---A-A-G-C-T-T---3'

3'---T-T-C-G-A-A---5'

Exercise | Q 1.5 | Page 291

Recombinant protein .................. is used to dissolve blood clots present in the body.

insulin

tissue plasminogen activator

relaxin

erythropoietin

Solution:

Recombinant protein tissue plasminogen activator is used to dissolve blood clots present in the body.

Exercise | Q 1.6 | Page 291

The recognition sequence of restriction enzymes is generally __________ nucleotide long.

2 to 4

4 to 8

8 to 10

14 to 18

Solution:

The recognition sequence of restriction enzymes is generally 4 to 8 nucleotides long.

Very short answer type question

Exercise | Q 2.1 | Page 291

Name the vector which is used in the production of human insulin through recombinant DNA technology.

Solution:

pBR322 vector is used in the production of human insulin through recombinant DNA technology.

Exercise | Q 2.2 | Page 291

Which cells from Langerhans of the pancreas do produce a peptide hormone insulin?

Solution:

Insulin is a peptide hormone produced by β-cells of islets of Langerhans of the pancreas.

Exercise | Q 2.3 | Page 291

Give the role of Ca++ ions in the transfer of the recombinant vector into the bacterial host cells.

Solution:

Ca++ ions assist the transfer of the recombinant vector into a bacterial host cell.

Expand the following acronym which is used in the field of protechnology.

Exercise | Q 2.4 | Page 291

YAC

Solution:

YAC: Yeast Artificial Chromosome

Exercise | Q 2.4 | Page 291

RE

Solution:

RE: Restriction Enzyme

Exercise | Q 2.4 | Page 291

dNTP

Solution:

dNTP: Deoxyribonucleoside triphosphate

Exercise | Q 2.4 | Page 291

PCR

Solution:

PCR: Polymerase Chain Reaction

Exercise | Q 2.4 | Page 291

GMO

Solution:

GMO: Genetically Modified Organism

Exercise | Q 2.4 | Page 291

MAC

Solution:

MAC: Mammalian Artificial Chromosome

Exercise | Q 2.5 | Page 291

Fill in the blanks and complete the chart.

GMO	Purpose
i. Bt cotton	____________
ii. _____________	Delay the softening of tomato during ripening.
iii. Golden rice	____________
iv. Holstein cow	____________

Solution:

GMO	Purpose
i. Bt cotton	Insect pest resistance
ii. Flavr savr tomato	Delay the softening of tomato during ripening.
iii. Golden rice	High vitamin A content
iv. Holstein cow	High milk yield capacity

Short answer type question

Exercise | Q 3.1 | Page 291

Explain the properties of a good or ideal cloning vector for rDNA technology.

Solution:

Following characteristic properties, a cloning vector must possess in order to be used in rDNA technology:

• A good vector should have the ability of independent replication so that as the vector replicates (through ori gene) and a large number of copies of the DNA insert will be formed.
• The vector should be able to easily introduce into host cells.
• A vector should have marker genes for antibiotic resistance.
• A vector must contain a unique cleavage site in one of the marker genes for the restriction enzyme.
• It should have at least suitable control elements like a promoter, operator, ribosomal binding sites, etc.
• The plasmids obtained naturally do not possess all the characteristics. Hence, they are constructed by inserting a gene for antibiotic resistance. eg. pBR322, pBR320, pACYC177 are the constructed plasmids. pBR322 is mostly used in rDNA technology in plants.

Exercise | Q 3.2 | Page 291

A PCR machine can raise the temperature up to 100°C but after that, it is not able to lower the temperature below 70°C automatically. Which step of PCR will be hampered first in this faulty machine? Explain why?

Solution:

i. If a PCR machine fails to lower the temperature below 70°C then the annealing step (in which primers attach to the respective ends of the DNA template) would be affected.

ii. The annealing step of PCR requires a temperature ranging between 40°C to 60°C therefore if a PCR machine fails to lower the temperature below 70°C, primers will not attach to the DNA templates.

Exercise | Q 3.3 | Page 291

In the process of rDNA technology, if two separate restriction enzymes are used to cut vector and donor DNA then which problem will arise in the formation of rDNA or chimeric DNA? Explain.

Solution:

i. Restriction enzymes cut the DNA at a specific recognition site and produce either sticky ends or blunt ends.

ii. For e.g., if we use the restriction enzyme EcoR I to cut vector DNA then it will produce vector DNA having sticky ends and if we use the Hind II restriction enzyme to cut donor DNA then it will produce donor DNA with blunt ends.

iii.  vector DNA to get ligated to the desired gene, they both must possess similar kind of ends i.e. both should have either blunt ends or sticky ends.

iv. If two separate restriction enzymes are used to cut vector and donor DNA then they will fail to form complementary base pairing and chimeric DNA will not be formed.

Exercise | Q 3.4 | Page 292

Match and write the pairs.

Recombinant protein	It’s used in or for
i. platelet-derived growth factor	a. Anemia
ii. α-antitrypsin	b. cystic fibrosis
iii. Relaxin	c. Haemophilia A
iv. Erythropoietin	d. Diabetes
v. Factor VIII	e. Emphysema
vi. DNase	f. Parturition
	g. Atherosclerosis

Solution:

Recombinant protein	It’s used in or for
i. platelet-derived growth factor	g. Atherosclerosis
ii. α-antitrypsin	e. Emphysema
iii. Relaxin	f. Parturition
iv. Erythropoietin	a. Anemia
v. Factor VIII	c. Haemophilia A
vi. DNase	b. cystic fibrosis

Long answer type question

Define and explain the term

Exercise | Q 4.1 | Page 292

Biopiracy

Solution:

Biopiracy is defined as ‘theft of various natural products and then selling them by getting a patent without giving any benefits or compensation back to the host country’.

i. For proper and lawful working of biopatent, the nation should be rich in bio-diversity, people residing there should have traditional knowledge and the nation should also have sufficient financial resources.

ii. However, it is generally observed that industrialized nations are rich in financial resources and technology but lack bio-diversity, whereas developing countries are rich in biodiversity and traditional knowledge but are short of financial resources and advanced technology. These situations lead to biopiracy.

iii. Industrialized nations have always been enjoying immense profits by patenting the indigenous biomedical knowledge and bioresources of third-world communities without paying any compensation to the indigenous group who originally developed such knowledge.

Example:

i. Texmati case: A strain of Basmati rice was patented by Texas-based company Rice Tec Inc with trade name Texmati. This patenting was illegal and unethical as Basmati is a long-grained, aromatic variety of rice indigenous to the Indian subcontinent. India fought a long legal battle after which the patent was canceled.

ii. Turmeric: Since ancient times, Indians have been using Haldi (Turmeric powder) as an antiseptic for healing wounds for killing pests, and for medicinal purposes. However, American companies have patented Turmeric and many medicinal plants of India. After a long legal battle, most of the patents have been revoked.

iii. Neem (Azadirachta indica): The patenting of the fungicidal properties of Neem was an example of biopiracy. The USDA and an American MNC W.R. Grace in the early 90s sought a patent from the European Patent Office (EPO) on the “method for controlling on plants by the aid of hydrophobic extracted neem oil.”

Exercise | Q 4.1 | Page 292

Biopatent

Solution:

Biopatent is a biological patent awarded for strains of microorganisms, cell lines, genetically modified strains, DNA sequences, biotechnological processes, product processes, products, and product applications.

Biopatents are awarded to recognize real innovative contributions made by the inventor to the cause of human welfare.

The awards are given to inculcate encouragement and values in developing scientific culture and in emphasizing the role of biology in shaping human society.

Indian patent allows ‘process patent’ and not the ‘product patent’. Biopatent allows the patent holder to exclude others from making, using, selling, or importing a protected invention for a limited period of time.

The duration of biopatents is five years from the date of the grant or seven years from the date of filing the patent application, whichever is less.

Exercise | Q 4.1 | Page 292

Bioethics

Solution:

Bioethics helps to study moral vision, decisions, and policies of human behaviour in relation to biological phenomena or events.

Ethics deals with ‘Life’ e.g. in vitro fertilization, sperm bank, gene therapy, cloning, gene manipulations, euthanasia, death, maintaining those who are in a comatose state, prenatal genetic selection, etc.

The era of biotechnology has brought a wide spectrum on new topics like cloning, transgenic, gene therapy, eugenics, rDNA technology, etc.

The use of all these has drawn a wide range of reactions in society.

Ethical aspects pertaining to the use of biotechnology seems to be more controversial and frightening.

These concerns are broadly summarized below: Use of animals causes great suffering to them; violation of integration of species caused due to transgenesis; transfer of human genes into animals and vice versa; indiscriminate use of biotechnology poses risk to the environment, health, and biodiversity.

The introduction of Genetically Modified Organisms (GMOs) has led to a wider debate on bioethical concerns affecting social, economic, and environmental spheres.

These include the effects on non-target organisms, insect resistance crops, gene flow, and the loss of diversity as well as the issue of interfering with nature.

Ethics in biotechnology also includes the general subject of what should and should not be done in using recombinant DNA techniques.

Exercise | Q 4.2 | Page 292

Explain the steps in process of rDNA technology with suitable diagrams.

Solution:

The steps involved in gene cloning are as follows:

i. Isolation of DNA (gene) from the donor organism:

• The desired gene to be cloned is obtained from the source organism (donor).
• Initially, the cells of the donor organism are sheared with the blender and treated with a suitable detergent.
• Genetic material from the donor is isolated and purified using several techniques.
• Isolated DNA can be spooled onto a glass rod.

ii. Cutting of the desired gene:

• Isolated purified DNA is then cleaved by using restriction enzymes i.e. restriction endonucleases.
• These enzymes cleave DNA at restriction sites and break the DNA into fragments.
• There are several types of restriction endonucleases.
• Cleaved DNA fragments have cohesive, sticky, staggered ends or blunt ends.
• From cleaved DNA fragments, a fragment containing the desired gene is isolated and selected for cloning. This is now called foreign DNA or passenger DNA.
• The desired gene can also be obtained directly from the genomic library or cDNA library.

iii. Insertion of a desired foreign gene into a cloning vector (vehicle DNA):

• The foreign DNA or passenger DNA is now inserted into a cloning vector or vehicle DNA.
• The most commonly used cloning vectors are plasmids of bacteria and bacteriophage viruses like lambda phage and M13.
• The most commonly used plasmid is pBR322.
• Plasmids are isolated from the vector organisms i.e. bacterium.
• By using the same restriction enzyme (which is used in the isolation of the desired gene from the donor), plasmid i.e. vector DNA is cleaved.
• Now by using enzyme DNA ligase, foreign DNA is inserted/ integrated into the vector DNA.
• The combination of vector DNA and foreign DNA is now called Recombinant DNA or Chimeric DNA and the technology is referred to as rDNA technology.

iv. Transfer of rDNA into suitable competent host or cloning organism:

• Finally, the recombinant DNA is transferred for expression into a competent host cell which is usually a bacterium.
• The host cell takes up naked rDNA by process of ‘transformation’ and incorporates it into its own chromosomal DNA which finally expresses the trait controlled by passenger DNA.
• The transfer of rDNA into a bacterial cell is assisted by divalent Ca++.
• The cloning organisms used in plant biotechnology are E. coli and Agrobacterium tumefaciens.
• The host/ competent cell which has taken up rDNA is now called a transformed cell.
• Foreign DNA can also be transferred directly into the naked cell or protoplast of the competent host cell, without using a vector.
• This is done by using techniques like electroporation, microinjection, lipofection, shotgun, ultra-sonification, biolistic method, etc. But in plant biotechnology, the transformation is through Ti plasmids of A. tumefaciens.

v. Selection of the transformed host cell:

• The transformation process generates a mixed population of transformed (recombinant) and non-transformed (non-recombinant) host cells.
• For the isolation of recombinant cells from non-recombinant cells, the marker gene of the plasmid vector is employed.
• For example, the pBR322 plasmid vector contains different marker genes (Ampicillin resistant gene and Tetracycline resistant gene).
• When the PstI restriction enzyme is used, it knocks out Ampicillin resistant gene from the plasmid, so that the recombinant cell becomes sensitive to Ampicillin.

vi. Multiplication of transformed host cell:

• Once transformed, host cells are separated by the screening process.
• In this step, the transformed host cells are introduced into fresh culture media.
• At this stage, the host cells multiply along with the replication of the recombinant DNA carried by them.

vii. Expression of the gene to obtain the desired product:

• The next step involves the production of desired products like alcohol, enzymes, antibiotics, etc.
• Finally, the desired product is separated and purified through downstream processing using a suitable bioreactor.

Exercise | Q 4.3 | Page 292

Explain the gene therapy.

Solution:

Gene therapy is the treatment of disease by replacing, altering, or supplementing a gene that is absent or abnormal and whose absence or abnormality is responsible for the disease.

The following are the different ways through which gene therapy is being used for the treatment of a disease or disorder:

1. Replace missing or defective genes;
2. Deliver genes that speed up the destruction of cancer cells;
3. Supply genes that cause cancer cells to revert back to normal cells;
4. Deliver bacterial or viral genes as a form of vaccination;
5. Deliver DNA to antigen expression and generation of immune response;
6. Supply of gene for impairing viral replication;
7. Provide genes that promote or impede the growth of new tissue; and
8. Deliver genes that stimulate the healing of damaged tissue.

Exercise | Q 4.3 | Page 292

Give two types of gene therapy.

Solution:

There are two forms of gene therapy based on the types of cells in which genes are delivered:

i. Germline gene therapy:

• In this method, healthy genes can be introduced into germ cells like sperms, eggs, early embryos.
• It allows the transmission of the modified genetic information to the next generation.
• Though it is highly effective in counteracting genetic disorders, it is not encouraged for application in human beings due to a variety of technical and ethical reasons.

ii. Somatic cell gene therapy:

• In this type, the gene is introduced only in somatic cells like bone marrow cells, hepatic cells, fibroblasts endothelium, and pulmonary epithelial cells, central nervous system, endocrine cells, and smooth muscle cells of blood vessels walls.
• Modification of somatic cells only affects the person being treated and the modified chromosomes cannot be passed on the future generations.
• Somatic cell gene therapy is the only feasible option and the clinical trials have already employed for the treatment of acquired disorders such as cancer and rheumatoid arthritis and blood disorders including SCID, Gaucher’s disease, familial hypercholesterolemia, hemophilia, phenylketonuria, cystic fibrosis, sickle cell anemia, Duchenne muscular dystrophy, emphysema, thalassemia, etc

Exercise | Q 4.4 | Page 292

How are the transgenic mice used in cancer research?

Solution:

Transgenic mice:

Transgenic mice that have been modified using a particular oncogene (cancer-causing gene) and thus developed a certain type of cancer, are useful to answer questions concerning the relationship between oncogenes and cancer development.

Theoretically, such animals can also be used for research into cancer treatment and prevention of malignancy.

In the laboratory, one such transgenic mouse model for the investigation of breast cancer was developed. The oncogenes Myc and ras were analyzed to find out if they lead to breast cancer in mice transformed with these genes.

Exercise | Q 4.5 | Page 292

Give the steps in PCR or polymerase chain reaction with suitable diagrams.

Solution:

Polymerase Chain Reaction (PCR) is the process of in vitro amplification of the gene of interest using a PCR machine.

i. PCR can generate a billion copies of the desired segment of DNA or RNA, with high accuracy and specificity, in a few hours.

ii. The process of PCR is completely automated and involves automatic thermal cycles for denaturation and renaturation of double-stranded DNA.

iii. The device required for PCR is called a thermal cycler.

iv. Requirements for polymerase chain reaction:

DNA containing the desired segment to be amplified

several molecules of four deoxyribonuclueoside triphosphates (dNTPs)

excess of two primer molecules

heat-stable DNA polymerase and

appropriate quantities of Mg++ ions.

Mechanism of PCR:

At the start of PCR, all the requirements are mixed together in ‘Eppendorf tube’ and the following operations are performed sequentially:

Step i: Denaturation

The reaction mixture is heated to a temperature (90–98oC) to separate two strands of desired DNA. This is called denaturation.

Step ii: Annealing

The mixture is allowed to cool (40–60oC) that permits the pairing of the primer to the complementary sequences in DNA. This step is called annealing.

Step iii: Primer extension / Polymerization

The temperature (70–75°C) allows thermostable Taq DNA polymerase to use single-stranded DNA as a template and adds nucleotides. This is called primer extension. It takes around two minutes duration.

v. One cycle takes around 3 to 4 minutes.

vi. To begin the second cycle, DNA is again heated to convert double-stranded DNA into single strands.

vii. In an automatic thermal cycler, the above three steps are automatically repeated 20-30 times. Thus, at the end of ‘n’ cycles, 2n copies of DNA segments are produced.

viii. The machine performs the entire operations automatically and precisely.

Exercise | Q 4.6 | Page 292

What is a vaccine?

Solution:

A vaccine is a biological preparation that provides active acquired immunity against a certain disease.

Exercise | Q 4.6 | Page 292

Give advantages of oral vaccines or edible vaccines.

Solution:

• The benefit of oral vaccines or edible vaccines is
• The comfort of administration as the use of needle-free vaccine administration eliminates the risk of transmitting blood-borne pathogens and can be performed by health workers without any medical training.
• Low cost, the Manufacturing cost is low as there is no need for special premises to manufacture them. The edible vaccine can be easily produced at a mass level in comparison to an animal system.
• Ease of storage. Vaccines produced by biotechnological methods are stable at room temperature, unlike a traditional vaccine, which needs cold chain storage, which multiplies the yearly cost to preserve vaccines

Exercise | Q 4.7 | Page 292

Enlist different types of restriction enzymes commonly used in rDNA technology? Write about their role.

Solution:

There are three types of restriction enzymes:

Type I – These enzymes function simultaneously as endonuclease and methylase e.g. EcoK.

Type II – These enzymes have separate activities for cleaving and methylation; they are more stable and are used in rDNA technology e.g. EcoRI, BglII; these enzymes cut DNA at specific sites within the palindrome. There are thousands of type II restriction enzymes that are recognized/ discovered.

Type III – These enzymes cut DNA at specific non-palindromic sequences e.g. HpaI, MboII.

Role of restriction enzymes:

Restriction enzymes either cut straight across the DNA in the region of palindrome to give blunt ends or cuts producing short, single-stranded projections at each end of DNA to produce, cohesive or sticky ends or staggered ends.

Exercise | Q 4.8 | Page 292

Enlist and write in brief about the different biological tools required in rDNA technology.

Solution:

The different biological tools required in rDNA technology:

i. Instruments: PCR, Agarose Gel Electrophoresis, SDS-PAGE 

Polymerase Chain Reaction (PCR) is the process of in vitro amplification of the gene of interest using a PCR machine.

1. PCR can generate a billion copies of the desired segment of DNA or RNA, with high accuracy and specificity, in a few hours.
2. The process of PCR is completely automated and involves automatic thermal cycles for denaturation and renaturation of double-stranded DNA.
3. The device required for PCR is called a thermal cycler.

Requirements for polymerase chain reaction:

1. DNA containing the desired segment to be amplified
2. several molecules of four deoxyribonuclueoside triphosphates (dNTPs)
3. excess of two primer molecules
4. heat-stable DNA polymerase and
5. appropriate quantities of Mg++ ions.
6. DNA replication through a polymerase chain reaction.

ii. Biological tools: Enzymes, Cloning Vectors, Competent host

1. Different enzymes used in rDNA technology are as follows: Lysozymes, Nucleases such as exonucleases, endonucleases, restriction endonucleases, DNA ligases, DNA polymerases, alkaline phosphatases, reverse transcriptase, etc.
2. Enzymes that cut the phosphodiester bonds of polynucleotide chains are called nuclease.
3. These are of two types- exonuclease and endonuclease.
4. Exonucleases cut nucleotides from the ends of DNA strands whereas endonuclease cut DNA from within.
5. The phosphodiester backbone at highly specific sites on both strands of the duplex is cut by these enzymes called restriction endonucleases or simply restriction enzymes.
6. The restriction enzymes are thus the molecular scissors that are used to recognize and cut DNA at specific sequences.
7. The sites recognized by them, are called recognition sequences or recognition sites.
8. Different restriction enzymes found in different organisms recognize different nucleotide sequences and therefore cut DNA at different sites.
9. The following characteristic properties a cloning vector must possess in order to be used in rDNA technology:
10. A good vector should have the ability of independent replication so that as the vector replicates (through ori gene) and a large number of copies of the DNA insert will be formed.
11. The vector should be able to easily introduce into host cells.
12. A vector should have marker genes for antibiotic resistance.
13. A vector must contain a unique cleavage site in one of the marker genes for the restriction enzyme.
14. It should have at least suitable control elements like a promoter, operator, ribosomal binding sites, etc.
15. The plasmids obtained naturally do not possess all the characteristics. Hence, they are constructed by inserting a gene for antibiotic resistance. e.g. pBR322, pBR320, pACYC177 are the constructed plasmids. pBR322 is mostly used in rDNA technology in plants.
16. Competent hosts (cloning organisms) used are usually bacteria like Bacillus haemophilus, Helicobacter pylori, and E. coli. Mostly E. coli is used for the transformation with recombinant DNA.

class 12 biology chapter 12 pdf

12.1 Biotechnology It is defined by different organizations in different ways. It has been brodly defined as ‘the development and utilization of biological forms, products or processes for obtaining maximum benifits to man and other forms of life’. 

According to OECD (Organization for Economic Cooperation and Development, 1981)- ‘It is the application of scientific and engineering principles to the processing of materials by biological agents to provide goods and service to the human welfare’. It uses scientific priciples of microbiology, genetics biochemistry, chemical engineering, mathematics, statistics, computers, industrial processes, etc.

 Biological agent means plants and animal cells, microorganisms, enzymes or their products. History of origin of biotechnology is as old as human civilization. Development of biotechnology in terms of its growth, occurred in two phases viz, Traditional biotechnology and Modern biotechnology. Traditional biotechnology (old biotechnology) was primarily based on fermentation technology using microorganisms as in the preparation of curd, ghee, soma, 

vinegar, yogurt, cheese making, wine making, etc. It became an art of kitchen in indian houses. It was more an art than science. Till that time people did not know as to how exactly the process occurs and the organisms causing this process. The contributions made by several chemists, biochemists and microbiologist, over the time, could explain the mechanism of process and also the nature of microorganisms causing the process.

During 1970 a new technique of ‘recombinant DNA technology was developed and then established by Stanley Cohen and Herbert Boyer in 1973. This technique has changed the overall outlook, then. The technique permits to change/ modify genetic (heritable) material for getting new specific products. The combination of biology and production technology based on genetic engineering evolved into modern biotechnology (new biotechnology).

There are two major features of technology that differenciate modern biotechnology from classical or old biotechnology viz,

 i. Capablity of science to change the genetic material for getting new specific products through rDNA technology, polymerase chain reaction (PCR), microarrays, cell culture and fusion, and bioprocessing. 

ii. Ownership of technology and its sociopolitical impact. Now the conventional industries, pharmaceutical industries, agro industries, food industries, etc. are also focussing attention to produce biotechnology- based products.

Principles and Processes of Biotechnology : Modern biotechnology is based on two core techniques viz. genetic engineering and chemical engineering. Genetic engineering deals with alteration of genetic material (DNA and RNA) while chemical engineering deals with maintaining sterile environment for manufacturing variety of useful products including vaccines, antibodies, enzymes, organic acids, vitamins, therapeutics, etc. 

Genetic engineering is defined as the manupulation of genetic material towards a desired end and in a directed and predetermined way, using in vitro process. Manipulation of genes involve repairing of the defective genes or replacing of defective genes by healthy genes or normal genes; artificially synthesizing of a totally new gene; transfer of genes into a new location or into a new organism; introducing an all together new gene; manipulation of genes for improvement of living organisms; combining of genes from two organisms, altering the genotype; gene cloning etc. Therefore, the genetic engineering is alternatively called recombinant DNA technology or gene cloning.

Technique of gene cloning and rDNA technology : In gene cloning, a gene of known function can be transferred from its normal location into a cell (that of course does not contain it) via a suitable vector. The transferred gene is replicated normally and is handed over to the next progeny 

A. Tools and techniques for gene cloning/  

 

rDNA technology : Before we venture into a procedure of gene cloning, let us know briefly, the basic requirements for the technique

I. Different instruments (devices) : Macromolecule such as DNA, RNA, proteins, etc. are synthesized in the living cells which vary in their molecular weight, solubility, presence of charges, absorbance of light, etc. Several techniques are used to isolate and charaterize the macromolecules. The size of different types of molecules varies and therefore their molecular weights also vary. 

The techniques used on the basis of molecular weight, are gel permeation, osmotic pressure, ion exchange chromatography, spectroscopy, mass spectrometry, electrophoresis, etc. Electrophoresis is the separation of charged molecules, applying an electric field. It is applied for the separation of DNA, RNA and proteins.

 DNA being negatively charged, migrates to anode. Small fragments of DNA molecules, move faster and thus separate faster. Use of Agarose gel electrophoresis, PAGE, SDA PAGE are the different methods of electrophoresis

Polymerase chain reaction (PCR) : Polymerase chain reaction (PCR) is another device used for gene cloning or gene multiplication in vitro. It is the amplification of gene of interest, through PCR. In 1985, Kary Mullis made an important discovery (contribution) in the form of an extremely powerful technique called polymerase chain reaction (PCR). PCR can generate a billion copies of the desired segment of DNA or RNA, with high accuracy and specificity, in a matter of few hours. The process of PCR is completely automated and involves automatic thermal cycles for denaturation and renaturation of double stranded DNA. 

The device required for PCR is called thermal cycler. PCR is in vitro amplification of a desired DNA segment, which requires : DNA containing the desired segment to be amplified, several molecules of four deoxyribonuclueoside triphosphates (dNTPs), excess of two primer molecules, heat stable DNA polymerase and appropriate quantities of Mg++ ions.

Examples of Biopiracy :

 • Patenting of Neem (Azadirachta indica) : The people of India in a variety of ways have used neem, since time immemorial. Indians have shared the knowledge of the properties of the neem with the entire world. Pirating this knowledge, the USDA and an American MNC W.R. Grace in the early 90s sought a patent from the European Patent Office (EPO) on the “method for controlling on plants by the aid of hydrophobic extracted neem oil.” The patenting of the fungicidal properties of Neem, was an example of biopiracy. 

• Patenting of Basmati : Basmati is a long-grained, aromatic variety of rice indigenous to the Indian subcontinent. In 1997 the US Patent and Trademark Office (USPTO) granted a patent to a Texas based American company Rice Tec Inc for “Basmati rice line and grains” having trade name Texmati. The patent application was based on 20 very broad claims on having “invented” the said rice. Due to peoples movement against Rice Tec in March 2001, the UPSTO has rejected all the claims.

• Haldi (Turmeric) Biopiracy : Two American researchers of Indian origin of the University of Mississippi Medical Center, put a claim to the US Patent and Trademark Office, maintaining that they had discovered haldi's healing properties. Surprisingly, they were granted a patent in March 1995 for something you had known for years and our ayurvedas for centuries.

 It meant they had exclusive rights over any such haldi drug and were in a position to make millions of dollars. The Council of Scientific and Industrial Research (CSIR) applied to the US Patent Office for a reexamination and they realized the mistake and cancelled the patent. 

This was after Indian scientists shouted from rooftops about how we are losing our traditional knowledge to marauding foreign companies who have started poaching on our ancient healing techniques. It is the need of hour to launch genetic literacy movement in Indian school and colleges for better understanding of opportunities and risks related to biotechnology and also to promote the safe and meaningful use of technologies of modern life sciences. 

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Balbharati solutions for Biology 12th Standard HSC for Maharashtra State Board
Chapter 1: Reproduction in Lower and Higher Plants
Chapter 2: Reproduction in Lower and Higher Animals
Chapter 3: Inheritance and Variation
Chapter 4: Molecular Basis of Inheritance
Chapter 5: Origin and Evolution of Life
Chapter 6: Plant Water Relation
Chapter 7: Plant Growth and Mineral Nutrition
Chapter 8: Respiration and Circulation
Chapter 9: Control and Co-ordination
Chapter 10: Human Health and Diseases
Chapter 11: Enhancement of Food Production
Chapter 12: Biotechnology
Chapter 13: Organisms and Populations
Chapter 14: Ecosystems and Energy Flow
Chapter 15: Biodiversity, Conservation and Environmental Issues