GSEB Class 12 Biology Solutions Chapter 12 Biotechnology and Its Applications

Question 1. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because -
a. bacteria are resistant to the toxin
b. toxin is immature;
c. toxin is inactive;
d. bacteria encloses toxin in a special sac.
Answer: (c) toxin is inactive
The Bt toxin protein is initially present as inactive protoxins. However, when an insect consumes this inactive toxin, the alkaline pH within its gut causes the crystals to solubilize, converting the protoxin into its active toxic form.
In simple words: The Bt toxin is produced in an inactive form within the bacteria, preventing self-harm. It becomes active only when ingested by insects, due to the alkaline conditions in their gut.

🎯 Exam Tip: Understanding the activation mechanism of Bt toxin (protoxin to active toxin due to alkaline pH) is crucial for explaining its specificity and function in pest control.

 

Question 2. What are transgenic bacteria? Illustrate using any one example.
Answer:
Transgenic bacteria are microorganisms engineered to carry cloned foreign genes, also referred to as genetically modified bacteria. These bacteria are utilized for various functions.
(a) For instance, two DNA sequences, which encode the A and B chains of human insulin, were introduced into the plasmid of *E. coli* bacteria. This transgenic *E. coli* then produced insulin chains, serving as "biochemical factories."
(b) Microbes have also been genetically modified to assist in cleaning up polluted environments. Examples include *Pseudomonas putida* used for oil spill remediation and *Pseudomonas* species for removing heavy metal pollutants. Additionally, *Acetobacter aerogans* aids in the decomposition of DDT, and *Flavobacterium* is used for the decomposition of 2,4-D.
In simple words: Transgenic bacteria are genetically engineered microbes containing foreign genes for specific purposes. An example is *E. coli* modified to produce human insulin.

🎯 Exam Tip: When providing examples for transgenic organisms, clearly state the organism, the gene introduced, and the resulting beneficial application or product.

 

Question 3. Compare and contrast the advantages and disadvantages of the production of genetically modified crops.
Answer:
**Advantages:**
• Increased crop yield
• Reduced reliance on pesticides
• Minimized need for fertilizer-resistant plants
• Development of disease-resistant and stress-tolerant crops
• Enhancement of nutritional content in plants
**Disadvantages:**
• Potential for gene flow, leading to cross-pollination with wild relatives
• Genetically modified crops might develop toxic metabolites through recombination
• Possible negative impact on the livelihoods of farmers in third-world countries
In simple words: Genetically modified crops offer benefits like higher yields and improved resistance but pose risks such as gene transfer to wild plants and potential socio-economic impacts on farmers.

🎯 Exam Tip: When comparing advantages and disadvantages, ensure you present balanced arguments, addressing both the scientific benefits and the potential ecological or societal concerns.

 

Question 4. What are Cry proteins? Name an organism that produces it. How has man exploited this protein to his benefit?
Answer:
Cry proteins are crystalline proteins produced by *Bacillus thuringiensis*, commonly known as Bt toxins. A gene named *cry* codes for this toxin. There are several types of *cry* genes; for instance, genes *cryIAc* and *cryIIAb* regulate cotton bollworms, while *cryIAb* controls the corn borer. Cry proteins are now expressed in crop plants, such as cotton, to create transgenic Bt-cotton plants.
In simple words: Cry proteins are natural insecticides from *Bacillus thuringiensis*. Humans use the genes encoding these proteins to genetically engineer crops like cotton, making them pest-resistant.

🎯 Exam Tip: Remember to specify the producing organism (*Bacillus thuringiensis*) and highlight how the protein's insecticidal property is harnessed in agriculture (e.g., Bt-cotton).

 

Question 5. What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Answer:
Gene therapy involves a range of techniques aimed at correcting gene defects identified in a child or embryo. This process includes inserting genes into a person's cells and tissues to treat specific diseases. The correction of a genetic defect typically involves delivering a functional normal gene into the individual or embryo, enabling it to assume the role of the non-functional gene and compensate for its absence.
Adenosine deaminase (ADA) enzyme is vital for proper immune system function. The disorder arises from the deletion of the gene responsible for ADA production. In some children, ADA deficiency can be treated through bone marrow transplantation, or by enzyme replacement therapy, where functional ADA is injected into the patient. However, both these methods do not offer a complete cure. As an initial step in gene therapy, lymphocytes from the patient's blood are cultured outside the body. A functional ADA cDNA, utilizing a retroviral vector, is then introduced into these lymphocytes, which are subsequently returned to the patient.
In simple words: Gene therapy corrects faulty genes by introducing healthy ones, as seen in ADA deficiency where functional genes are added to lymphocytes to restore immune function.

🎯 Exam Tip: When explaining gene therapy, clearly state its objective (correcting gene defects) and use a specific example like ADA deficiency, detailing the steps involved for better clarity.

 

Question 6. Diagrammatically represent the experimental steps in cloning and expressing a human gene (say the gene for growth hormone) into a bacterium like E. coli?
Isolate gene for growth hormone
↓
Clone into a plasmid DNA
↓
Transform into E.coli
↓
The growth hormone accumulates in the E.coli cell
In simple words: To clone and express a human gene in *E. coli*, first isolate the gene, insert it into a plasmid, introduce the plasmid into *E. coli*, and then the bacterium will produce the desired protein.

🎯 Exam Tip: For processes like cloning, clearly outline each step in a logical, sequential manner, ensuring the flow is easy to understand, even without a visual diagram.

 

Question 7. Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and the chemistry of oil?
Answer:
The specific composition of fatty acids dictates the unique characteristics of oil in each plant. Most oils consist of one mole of glycerol and three moles of fatty acids. Based on the chemical nature of plant oils, we can engineer recombinant bacteria capable of synthesizing these specific oils and subsequently extracting them from the seeds.
In simple words: Recombinant DNA technology can create bacteria that synthesize specific plant oils. This allows for controlled production and easier extraction of oils from seeds.

🎯 Exam Tip: Focus on linking the understanding of oil chemistry (fatty acids, glycerol) with the application of rDNA technology to engineer organisms for targeted oil synthesis and extraction.

 

Question 8. Find out golden rice.
Answer:
Golden rice is a genetically engineered variety of rice designed to contain high levels of vitamin A.
In simple words: Golden rice is a genetically modified rice enriched with vitamin A to address nutritional deficiencies.

🎯 Exam Tip: For direct definitions, be concise and accurate, highlighting the key modification and its purpose, like vitamin A enhancement in golden rice.

 

Question 9. Does our blood have proteases and nucleases?
Answer:
Yes, our blood does contain proteases and nucleases. They play a role in processes like the formation of a blood clot.
In simple words: Yes, blood contains proteases and nucleases, which are involved in blood clotting.

🎯 Exam Tip: When answering simple factual questions, provide a direct answer followed by a brief, relevant functional context if applicable.

 

Question 10. Consult the internet and find out how to make orally active protein pharmaceuticals. What is the major problem to be encountered?
Answer:
Orally active proteins can be produced using DNA technology. For instance, hirudin, a blood-clotting protein, has been successfully produced in the seeds of *Brassica napus*. The transgenic cow named Rosie produces human protein alpha-lactalbumin. However, a significant problem is that such proteins may trigger allergic reactions in some individuals.
In simple words: Orally active protein pharmaceuticals can be made using genetic engineering in plants or animals, but a main challenge is the potential for allergic reactions in patients.

🎯 Exam Tip: When discussing protein pharmaceuticals, remember to address both the production method (biotechnology) and the critical challenge (allergic reactions or digestion in the gut).

 

GSEB Class 12 Biology Biotechnology And Its Applications Additional Important Questions And Answers

Question 1. Expand the following short forms related to biotechnology,
a. dsRNA
b. RNAi
c. Bt
d. G.M.O
e. ADA
f. PCR
g. ELISA
h. GEAC
Answer:
a. double-stranded Ribonucleic Acid
b. Ribonucleic Acid interference
c. *Bacillus thuringiensis*
d. Genetically Modified Organisms
e. Adenosine deaminase
f. Polymerase Chain Reaction
g. Enzyme-Linked Immunosorbent Assay
h. Genetic Engineering Approval Committee
In simple words: These are common abbreviations for key terms and techniques in biotechnology, such as double-stranded RNA, RNA interference, *Bacillus thuringiensis*, Genetically Modified Organisms, Adenosine Deaminase, Polymerase Chain Reaction, Enzyme-Linked Immunosorbent Assay, and Genetic Engineering Approval Committee.

🎯 Exam Tip: Memorize the full forms of common abbreviations in biotechnology, as these are frequently tested in exams.

 

Question 2. What is the significance of the process of RNA inference (RNAi) in eukaryotic organisms?
Answer:
RNA interference (RNAi) is a cellular defense mechanism found in eukaryotic organisms, primarily involving the silencing of messenger RNA (mRNA).
In simple words: RNA interference is a natural defense mechanism in eukaryotes that silences specific genes by blocking their messenger RNA.

🎯 Exam Tip: When asked about the significance of a biological process, state its primary role and where it occurs. For RNAi, emphasize its role in gene silencing and eukaryotic defense.

 

Question 3. The name of the gene which encodes for the toxin called crystal protein in Bacillus thuringiensis is 'cry'. What are the different types of 'cry' genes and name the type of insects controlled by each type?
Answer:
The gene encoding the crystal protein toxin in *Bacillus thuringiensis* is called 'cry'.
Different types of *cry* genes include *Cry IAc*, *Cry IIAb*, and *Cry IAb*.
*Cry IAc* and *Cry IIAb* primarily control cotton bollworms.
*Cry IAb* is effective against the corn borer.
In simple words: The 'cry' gene produces Bt toxins. Specific 'cry' genes like *Cry IAc* and *Cry IIAb* target cotton bollworms, while *Cry IAb* targets corn borer.

🎯 Exam Tip: It is important to know specific *cry* gene names and the pests they target, as this demonstrates a detailed understanding of Bt technology.

 

Question 4. What was the specialty of the milk produced by the transgenic cow, Rosie?
Answer:
The milk produced by the transgenic cow, Rosie, was special because it contained human protein alpha-lactalbumin at a concentration of 2.4 grams per liter, which is nutritionally superior and more balanced for human babies.
In simple words: Rosie, a transgenic cow, produced milk enriched with human alpha-lactalbumin, making it more nutritious for human infants.

🎯 Exam Tip: When discussing transgenic animals like Rosie, focus on the specific human protein produced and its direct benefit or application.

 

Question 5. Name the nematode which infects the roots of tobacco plants and was treated with the help of RNA interference.
Answer:
The nematode that infects the roots of tobacco plants and was treated using RNA interference is *Meloidogyne incognitia*.
In simple words: The nematode *Meloidogyne incognitia* infects tobacco plant roots and was controlled using RNA interference.

🎯 Exam Tip: Be precise with scientific names and the biotechnology application used. For this question, *Meloidogyne incognitia* and RNAi are key terms.

 

Question 6. Give a reason for each of the following.
1. Insulin cannot be administered orally to diabetic patients.
2. Biopiracy affects India the most.
Answer:
1. Insulin is a polypeptide, which means it is a protein. In the alimentary canal, it would be digested by peptidases, rendering it ineffective if administered orally.
2. India is particularly affected by biopiracy because it possesses rich biodiversity and extensive traditional knowledge related to the utilization of bio-resources, more so than many other countries.
In simple words: Insulin cannot be taken orally because it is a protein and would be digested. India is highly affected by biopiracy due to its vast biodiversity and traditional knowledge of bio-resources.

🎯 Exam Tip: For 'reason why' questions, provide clear, scientifically accurate explanations. For example, specify insulin's polypeptide nature for its oral ineffectiveness.

 

Question 7. Bt toxin seen inside Bt cotton exists in an inactive form. But when a pest feeds on Bt cotton, it dies. How does the toxin in the cotton plants kill the pest?
Answer:
When an insect pest consumes the inactive Bt toxin, the alkaline pH within its gut causes the toxin crystals to solubilize and convert into an active form. This activated toxin then binds to the surface of the midgut epithelial cells, creating pores. These pores lead to cell swelling and lysis, ultimately causing the death of the insect.
In simple words: The inactive Bt toxin becomes active in the insect's alkaline gut, creating pores in gut cells, causing them to swell and lyse, leading to the pest's death.

🎯 Exam Tip: Highlight the crucial role of alkaline pH in the insect gut and the mechanism of pore formation in epithelial cells leading to pest mortality.

 

Question 8. Mention the uses of cloned genes in, molecular diagnostics.
Answer:
• Cloned genes are utilized as probes to detect the presence of their complementary DNA strands; a mutated gene will not hybridize with the probe and thus will not appear on photographic film.
• When cloned genes are expressed to produce recombinant proteins, they aid in the development of sensitive diagnostic techniques.
In simple words: Cloned genes are used in diagnostics as probes to identify specific DNA sequences and to produce recombinant proteins for sensitive detection methods.

🎯 Exam Tip: When describing the uses of cloned genes in molecular diagnostics, emphasize their roles as probes for detection and their contribution to producing diagnostic proteins.

 

Question 9. In tobacco plants, a nematode Meloidogyne incognita infects the roots of tobacco plants and causes a great reduction in yield. To prevent this nematode infection a new method was introduced called RNA interference (silencing of specific mRNA). Briefly explain this method done in tobacco plants using Agrobacterium vectors.
Answer:
Nematode-specific genes were introduced into the tobacco host plant using *Agrobacterium* vectors. The DNA introduction was designed to produce both sense and anti-sense RNA within the host cells. These two RNA strands then combined to form a double-stranded RNA (dsRNA), which initiated RNA interference (RNAi). This RNAi mechanism subsequently silenced the specific messenger RNA (mRNA) of the nematode, thereby preventing the parasite from surviving in the host plant.
In simple words: RNA interference (RNAi) in tobacco plants against *Meloidogyne incognitia* involves introducing nematode-specific genes via *Agrobacterium* to produce double-stranded RNA, silencing the nematode's mRNA and preventing infection.

🎯 Exam Tip: Ensure you describe the entire process: gene introduction using *Agrobacterium*, production of sense and anti-sense RNA, dsRNA formation, and the subsequent silencing of nematode mRNA.

 

Question 10. The development of biotechnology has made an immense impact in the area of health care. Briefly explain any three such developments with examples.
Answer:
i. **Genetically engineered insulin:** Initially, two DNA sequences corresponding to the A and B chains of human insulin were introduced into *E. coli* plasmids to produce these chains separately. The extracted A and B chains were then combined by creating disulfide bonds to form functional human insulin.
ii. **Gene therapy:** Gene therapy encompasses various methods for correcting gene defects diagnosed in children or embryos. For instance, in ADA deficiency treatment, lymphocytes from the patient's blood are cultured outside the body, and a functional ADA cDNA (using a retroviral vector) is introduced into them before returning them to the patient.
iii. **Molecular diagnosis:** Biotechnology allows for the detection of very low concentrations of bacteria or viruses through the amplification of their nucleic acid using PCR. This technique is now routinely employed to detect mutations in genes in suspected cancer patients and to identify HIV in individuals suspected of having AIDS.
In simple words: Biotechnology has revolutionized healthcare through developments like genetically engineered insulin for diabetes, gene therapy to correct genetic defects (e.g., ADA deficiency), and molecular diagnostics like PCR for early disease detection.

🎯 Exam Tip: When asked for developments in healthcare, provide specific examples for each development (e.g., insulin for diabetes, ADA deficiency for gene therapy, PCR for molecular diagnosis).

 

Question 11. ELISA test is done to detect HIV in AIDS patients. What is the principle behind this test?
Answer:
The ELISA (Enzyme-Linked Immunosorbent Assay) test operates on the principle of antigen-antibody interaction. An infection by a pathogen can be identified either by detecting the presence of the pathogen's antigen or by detecting the antibodies produced by the body against that pathogen.
In simple words: The ELISA test detects HIV by recognizing the specific interaction between HIV antigens and the antibodies produced by the patient's immune system.

🎯 Exam Tip: For ELISA, the core principle to remember is the specific binding between antigens and antibodies, which forms the basis for detecting either the pathogen or the immune response.

 

Question 12. Transgenic animals are animals that have had their DNA manipulated to possess and express an extra gene. Comment on some of the areas where these transformed organisms are used.
Answer:
a. **To study normal physiology and development:** Transgenic animals are specifically engineered to enable the study of gene regulation and their impact on the body's normal functions and developmental processes.
b. **Production of useful products:** Transgenic animals can be created to produce beneficial biological products by introducing DNA segments that code for particular substances.
c. **Testing vaccine safety:** Some transgenic organisms, such as mice, are being developed and used to test the safety of vaccines before they are administered to humans.
In simple words: Transgenic animals, with manipulated DNA, are used for studying development, producing valuable biological products, and testing vaccine safety.

🎯 Exam Tip: When listing applications of transgenic animals, categorize them clearly (e.g., research, product production, safety testing) and provide brief explanations for each.

 

Question 13. Transgenic organisms are used by humans in various fields, especially to test the action of vaccines before they are used in humans. According to your opinion is there any ethical issue in such experiments? Comment.
Answer:
Yes, ethical standards are indeed required to assess the morality of all human activities that could potentially benefit or harm living organisms. The manipulation of living organisms by the human race cannot continue without proper regulation.
In simple words: Yes, there are ethical concerns with using transgenic organisms for testing; clear regulations are needed to ensure responsible manipulation of living beings.

🎯 Exam Tip: When discussing ethical issues, emphasize the need for regulatory frameworks and moral considerations to govern biotechnological practices involving living organisms.

 

Question 14. Suppose a foreign company applies for patent for a medicine made from turmeric. Turmeric is indigenously used in India as a medicine for skin diseases.
a. What is your opinion against such a theft of knowledge?
b. What do you call such an unauthorised use of bioresources?
Answer:
a. This represents an exploitation of our traditional knowledge, which should be protected from unauthorized use by others.
b. Such unauthorized use of bio-resources is termed biopiracy.
In simple words: Patenting traditional knowledge like turmeric medicine is theft of intellectual property, which is known as biopiracy, and must be prevented.

🎯 Exam Tip: Clearly define biopiracy and explain why traditional knowledge, particularly from biodiverse countries like India, needs protection from unauthorized exploitation.

 

Question 15. Genetic modification of organisms can have unpredictable results when such organisms are introduced into the ecosystem. Is there any regulatory authority in India to monitor such development of GM crops? Give a brief account.
Answer:
Yes, the Genetic Engineering Approval Committee (GEAC) is an organization established by the Indian government. Its mandate is to make decisions concerning the validity of GM research and to ensure the safety of introducing GM organisms for public services.
In simple words: The GEAC in India regulates the development and introduction of genetically modified crops, overseeing research validity and safety due to potential unpredictable ecosystem impacts.

🎯 Exam Tip: When asked about regulatory bodies, state the full name of the organization (GEAC) and its primary functions (validity of research, safety of introduction).

 

Question 16. Define the term biopiracy. Explain the issue of Basmati rice patent in this context.
Answer:
Biopiracy refers to the use of bio-resources by multinational companies and other organizations without obtaining proper authorization from the concerned countries and people, and without providing compensatory payment.
Regarding Basmati rice, it has been cultivated in India for centuries. However, an American company obtained patent rights on Basmati, claiming to have developed a new variety. This 'new variety' was, in fact, a combination of traditional Indian farmer's varieties and some semi-dwarf varieties. This new patent grants the company the right to prevent others from selling Basmati rice, despite its long history of cultivation in India.
In simple words: Biopiracy is the unauthorized exploitation of bio-resources and traditional knowledge, as exemplified by a company patenting Basmati rice, which is a traditional Indian variety, without fair compensation or permission.

🎯 Exam Tip: For definitions, provide a clear and comprehensive explanation. For examples like Basmati rice, explain how it fits the definition of biopiracy by detailing the unauthorized patenting of traditional varieties.

 

Question 17. There are several arguments against Genetically Modified crops (G.M crops). Organisations like 'Green Peace' protest against the cultivation of G.M. crops. Suppose you are also a protestor, what will be your two main arguments against G.M. crops?
Answer:
i. Genetically modified (GM) crops may cross-fertilize with natural varieties, potentially introducing undesirable characteristics into wild plant populations.
ii. Since GM crops contain genes from other organisms, such as bacteria, there is a risk that these genes could lead to the production of toxic chemicals harmful to humans.
In simple words: My arguments against GM crops would be the risk of gene transfer to wild plants and the potential for new toxic chemicals harmful to humans due to foreign genes.

🎯 Exam Tip: When presenting arguments against GM crops, focus on environmental concerns (gene flow) and potential health risks (toxic metabolites) for a balanced perspective.

 

Question 18. Biopiracy affects developing countries like India more than industrialized nations because our country is rich in …………. and ……………. related to bio-resources.
(Bioetics/Biodiversity/Biopatent, Traditional resources/Traditional cultivation/Traditional knowledge)
Answer:
Biopiracy affects developing countries like India more than industrialized nations because our country is rich in **Biodiversity** and **Traditional knowledge** related to bio-resources.
In simple words: Biopiracy disproportionately impacts developing countries like India because they possess vast biodiversity and extensive traditional knowledge about bio-resources.

🎯 Exam Tip: Identify the key natural and cultural assets (biodiversity, traditional knowledge) that make developing countries particularly vulnerable to biopiracy.

 

Question 19. Transgenic animals that produce useful biological products can be created by biotechnology. In 1997 the first transgenic cow was produced. Name the cow and the significance of its milk.
Answer:
The first transgenic cow, produced in 1997, was named Rosie. The milk produced by Rosie contained human alpha-lactalbumin protein and was nutritionally a more balanced product for human babies compared to natural cow milk.
In simple words: The first transgenic cow was Rosie, whose milk was significant for containing human alpha-lactalbumin, making it nutritionally superior for human infants.

🎯 Exam Tip: For specific historical examples like "Rosie," ensure you recall both the name and the key characteristic or benefit associated with it.

 

Question 20. PCR is used to amplify desired DNA a billion times. It is also used in the molecular diagnosis of human disorders. Explain.
Answer:
PCR (Polymerase Chain Reaction) is routinely employed to detect HIV in individuals suspected of having AIDS. It is also used to identify mutations in genes in suspected cancer patients. This powerful technique is also vital for identifying many other genetic disorders.
In simple words: PCR is used for molecular diagnosis to detect HIV in AIDS patients, identify genetic mutations in cancer, and diagnose various other genetic disorders by amplifying DNA.

🎯 Exam Tip: When explaining PCR's role in diagnostics, list specific applications like HIV detection, cancer mutation identification, and general genetic disorder diagnosis.

 

Question 21. Name any three techniques related to biotechnology that help in the early diagnosis of some diseases.
Answer:
• Recombinant DNA technology
• Polymerase Chain Reaction (PCR)
• Enzyme-Linked Immunosorbent Assay (ELISA)
In simple words: Three biotechnology techniques aiding early disease diagnosis are recombinant DNA technology, Polymerase Chain Reaction (PCR), and Enzyme-Linked Immunosorbent Assay (ELISA).

🎯 Exam Tip: Be ready to list and briefly describe key diagnostic techniques, focusing on how each method (e.g., DNA manipulation, amplification, antigen-antibody detection) contributes to early diagnosis.

 

Question 22. Briefly explain the structure of human insulin. What was the main challenge for production of insulin using rDNA technique?
Answer:
Human insulin is composed of two short polypeptide chains, A and B, which are connected by disulfide bridges. Insulin is initially synthesized as a prohormone that includes an extra segment called the C-peptide. This C-peptide is not present in mature insulin and is removed during the maturation process. The primary challenge in producing insulin using recombinant DNA techniques was accurately assembling the insulin into its mature, active form.
In simple words: Human insulin has A and B chains linked by disulfide bridges, initially synthesized with a C-peptide that's removed during maturation. The main challenge in rDNA production was correctly assembling these chains into functional insulin.

🎯 Exam Tip: Focus on insulin's two-chain structure, the role of the C-peptide in proinsulin, and the specific challenge of proper assembly for rDNA production.

 

Question 23. List any four advantages of genetically modified crop plants over their wild domesticated relatives.
Answer:
Advantages of genetically modified plants include:
• Increased tolerance to abiotic stresses (e.g., cold, drought, salt, heat)
• Reduced dependence on chemical pesticides (leading to pest-resistant crops)
• Contribution to reducing post-harvest losses
• Enhanced efficiency in mineral usage by plants
• Improved nutritional value of food (e.g., Vitamin A enriched rice)
In simple words: Genetically modified crops offer advantages such as improved stress tolerance, reduced pesticide use, lower post-harvest losses, better nutrient uptake, and enhanced nutritional content compared to traditional varieties.

🎯 Exam Tip: When listing advantages, categorize them for clarity, such as environmental tolerance, pest resistance, yield improvement, and nutritional enhancement.

 

Question 24. In the case of Bt cotton, how does the toxic insecticide protein produced by the bacterium kills the insect pest but not the cell of Bacillus thuringiensis where the toxic protein is generated?
Answer:
Certain strains of *Bacillus thuringiensis* generate proteins that are lethal to various insects, including lepidopterans like the tobacco budworm and armyworm. During a specific growth phase, *Bt* forms protein crystals that contain a toxic insecticidal protein. However, this toxin does not harm the *Bacillus* itself because the Bt toxin protein exists as inactive protoxins. Once an insect ingests the inactive toxin, the alkaline pH in its gut solubilizes these crystals, converting the protoxin into its active form. The activated toxin then binds to the surface of the midgut epithelial cells, creating pores that cause cell swelling and lysis, ultimately leading to the insect's death.
In simple words: Bt toxin is produced as an inactive protoxin in *Bacillus thuringiensis*, so it doesn't harm the bacteria. Ingested by insects, the toxin becomes active in their alkaline gut, binding to cells, forming pores, and causing cell lysis, leading to the pest's death.

🎯 Exam Tip: Emphasize the two key conditions for Bt toxin's action: its inactive protoxin form in bacteria and its activation by the alkaline pH in the insect gut, followed by pore formation and cell lysis.

 

Question 25. A multinational company (XYZ) marketed a medicine extracted from medicinal herbs grown in the sprawling fields in a foreign country. This herb is found only in our country and no compensation was paid or permission taken from relevant authorities.
i. What is the term used to refer to such an act committed by a multinational company?
ii. Justify the meaning of the term.
iii. What has our government done to prevent such deeds?
Answer:
i. The term used to refer to such an act by a multinational company is Biopiracy.
ii. Biopiracy is defined as the utilization of bio-resources by multinational companies and other organizations without obtaining proper authorization from the countries and populations concerned, and without providing fair compensatory payment.
iii. The Indian Parliament recently passed the second amendment to the Indian Patent Bill. This amendment addresses such issues by incorporating considerations like patent terms, emergency provisions, and initiatives for research and development.
In simple words: This scenario describes biopiracy, which is the unauthorized use of bio-resources and traditional knowledge without compensation. The Indian government has addressed this by amending the Indian Patent Bill.

🎯 Exam Tip: For biopiracy questions, define the term clearly, explain its components (unauthorized use, no compensation), and mention any relevant legal actions taken by the government.

 

Question 26. How has biotechnology been applied in each of the following?
i. In curing diabetes mellitus
ii. In raising pest-resistant plants
iii. In producing more nutritionally balanced milk.
Do you think it is ethical to manipulate organisms for human benefits? Justify your answer.
Answer:
i. **In curing diabetes mellitus:** Genetically engineered insulin is synthesized as a prohormone containing an extra C-peptide, which is subsequently removed during maturation into active insulin. The challenge with rDNA techniques was to correctly assemble insulin into its mature form, which has now been overcome, providing a vital treatment for diabetes.
ii. **In raising pest-resistant plants:** Using *Agrobacterium* vectors, nematode-specific genes are introduced into host plants. This DNA insertion causes the host cells to produce both sense and antisense RNA. These complementary RNA strands form a double-stranded RNA (dsRNA), initiating RNA interference (RNAi) that specifically interferes with the nematode's mRNA, preventing the parasite's survival. This protects the transgenic plant from pests.
iii. **In producing more nutritionally balanced milk:** Transgenic animals are created to produce useful biological products. For example, the first transgenic cow, Rosie, was engineered to produce human protein alpha-lactalbumin in her milk. This modified milk was more nutritionally balanced and suitable for human babies than regular cow's milk.
The manipulation of living organisms by humans cannot proceed unchecked. Regulation is essential, and the biological significance of such alterations is paramount. Genetic modification of organisms can lead to unpredictable outcomes when introduced into ecosystems. The Indian government has established the Genetic Engineering Approval Committee (GEAC) to review the validity of GM research and ensure the safety of introducing GM organisms for public use. This committee also considers the ethical implications, especially regarding the use of genetic material, plants, and other biological resources that have historically been identified, developed, and used by farmers and indigenous communities.
In simple words: Biotechnology offers solutions for diabetes (engineered insulin), pest control (RNAi in plants), and improved nutrition (transgenic milk). While beneficial, the ethical manipulation of organisms requires strict regulation by bodies like GEAC due to potential unpredictable ecological and social impacts.

🎯 Exam Tip: For applications, ensure you provide concise, accurate explanations with relevant examples. For the ethical component, emphasize the need for regulation, considering both the benefits and potential risks to justify the ethical stance.

 

Question 27. You have developed a GM organism. Which government organization will you approach to obtain clearance for its mass production? Why is such a body necessary? Give two reasons.
Answer:
To obtain clearance for the mass production of a genetically modified (GM) organism, I would approach the Genetic Engineering Approval Committee (GEAC), established by the Indian government.
Such a body is necessary for the following reasons:
• This body is crucial for monitoring the ethical implications of all human activities that could potentially benefit or harm living organisms.
• It is responsible for making decisions regarding the validity of GM research and ensuring the safety of introducing GM organisms for public use.
In simple words: I would approach GEAC for clearance of my GM organism. This body is essential to ensure ethical practices and to guarantee the safety of GM organisms before they are introduced for mass production.

🎯 Exam Tip: Identify the correct regulatory body (GEAC) and clearly articulate its dual role: ensuring ethical considerations and guaranteeing the safety of GM products for environmental and public health.

 

Question 28. (a) Write the disadvantages of human use of insulin from other animal sources
(b) What are the concerns about transgenic insulin?
Answer:
(a) Disadvantages of human use of insulin from other animal sources:
• It can cause allergic reactions.
• It may lead to other types of adverse reactions.
(b) Concerns about transgenic insulin:
• The primary concern involved the accurate removal of the C-peptide during maturation.
• Another challenge was correctly assembling the A and B polypeptide chains to form a mature, active insulin molecule.
In simple words: Animal insulin can cause allergies or other reactions. For transgenic insulin, the main concerns were precisely removing the C-peptide and correctly assembling the A and B chains into a mature form.

🎯 Exam Tip: Differentiate between issues with animal-derived insulin (allergies) and challenges in producing transgenic insulin (C-peptide removal, chain assembly).

 

Question 29. What is somatic hybridization?
Answer:
Somatic hybridization is a process that involves fusing protoplasts from mature cells of two different varieties or species of plants in a suitable nutrient culture medium.
In simple words: Somatic hybridization is the fusion of plant cell protoplasts from different varieties or species to create a hybrid in a culture medium.

🎯 Exam Tip: For definitions, clearly state the key components of the process, such as "fusing protoplasts" and "different varieties or species of plants."

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