Important Questions for CBSE Class 12 Biology Chapter 12 - Biotechnology and Its Applications 2024-25

Very Short Questions and Answers (1 Marks Questions)

1. Name the technique based on the principle of antigen-antibody interaction used in the detection of a virus (HIV).

Ans: The technique based on the principle of antigen-antibody interaction used in the detection of a virus (HIV) is ELISA(Enzyme-linked Immuno-Sorbent Assay).

2. The development of a transgenic food crop may help in solving the problem of night blindness in the developing countries, name this crop plant.

Ans: Golden Rice is a transgenic food crop that may help in solving the problem of night blindness in developing countries. 

3. Which nematode infects the roots of tobacco plants and causes a great reduction in yield?

Ans: Meloidogyne Incognita is the nematode that infects the roots of tobacco plants and causes a great reduction in yield.

4. The first transgenic cow produced human protein-enriched milk. Name the cow and the protein found in milk.

Ans: Rosie, is the first transgenic cow, it produced human protein-enriched milk. Alpha-lactalbumin is the protein found in milk.

5. The insulin produced using recombinant DNA technology is more advantageous than the insulin extracted from the pancreas of slaughtered cattle and pigs. How? 

Ans: Insulin obtained from animal sources causes allergy and the production of insulin by killing animals leads to animal cruelty. So recombinant DNA technology is advantageous over all that.

6. Name two pest-resistant plants produced by using recombinant DNA technology. 

Ans: Bt Cotton, Bt Corn, BtBrinjal are pest-resistant plants produced by using recombinant DNA technology.

7. Name the genetically engineered human Insulin? 

Ans: Humulin is the genetically engineered human Insulin.

8. Write the Scientific name of a nematode that attacks the root of a tobacco plant? 

Ans: Meloidogyne Incognita is the Scientific name of a nematode that attacks the root of a tobacco plant.

9. Define a patent? 

Ans: A patent is the government's protection for a biological material innovator, granting him the exclusive right to manufacture, exploit, use, and sell an innovation for a certain period of time.

10. Expand GEAC.

 Ans: Genetic Engineering Approval Committee is the expansion of GEAC.

11. Name the first transgenic cow?

Ans: Rosie is the name of the first transgenic cow.

12. Which vaccine was being tested on mice? 

Ans: Polio vaccine was being tested on mice.

13. Name the bacterium which is used to produce insect-resistant plants by genetic engineering. 

Ans: Bacillus thuringiensis is a bacterium that is used to produce insect-resistant plants by genetic engineering. 

14. Name any disease against which vaccine is developed by Recombinant DNA technology. 

Ans: Hepatitis B is the disease against which vaccines are developed by Recombinant DNA technology. 

15. Name the technique which is used to detect HIV in Suspected AIDS patients? 

Ans: PCR (polymerase chain reaction)  is the technique that is used to detect HIV in Suspected AIDS patients.

16. Name any two diseases for which transgenic mice are used as model organisms?

 Ans: Rheumatoid Arthritis cystic fibrosis is two diseases for which transgenic mice are used as model organisms.

 17. What is the difference between ‘Cry’ & ‘CRY’?

Ans: Cry is the gene that codes for Bt-toxin which is an insecticidal protein while CRY is the protein coded by cry genes. 

18. Name any one disease for which gene therapy has been proved effective? 

Ans: Adenosine deaminase deficiency (ADA)is the disease for which gene therapy has been proved effective.

Short Questions and Answers (2 Marks Questions)

1. What are the two methods for correcting ADA deficiency in a child?

Ans: Enzyme replacement therapy and bone marrow transplantation with a functional ADA enzyme.

2. Some crop plants are modified genetically by manipulating their genes. How are they made beneficial? 

Ans: Abiotic stress tolerance; pest resistance; reduced post-harvest losses; enhanced nutritional value of food.

3. GEAC is one of the organizations set up by the Indian Government. Write its full form. Give its two objectives.

Ans: The Genetic Engineering Approval Committee (GEAC) is a body that oversees the approval of genetic engineering projects.

The following are the goals of the GEAC: 

1. Make judgments about the legitimacy of GM research.

2. The introduction of GMOs for public use is safe.

4. “Industrialised nations are exploiting the bioresources of under industrialized nations. Justify the statement with a suitable example.

 Ans. The genetic resources of developing countries, such as India, are being collected and patented by industrialized nations. Basmati rice was patented by an American company. Bioresource-derived valuable biomolecules are patented and exploited for commercial purposes.

5. What is Golden rice? What is its advantage? 

Ans. Golden rice is a transgenic rice type that has a gene that codes for a precursor to Vitamin A. This type has green-yellow grains and is high in Vitamin A, making it nutritionally beneficial.

6. What are the three critical research areas in the field of Biotechnology?

Ans. Three critical research areas in the biotechnology field are given below:

1. Supplying the best catalyst in the form of a better creature, usually a microbe or a pure enzyme.

2. Using engineering to create ideal circumstances for a catalyst to function.

3. Purification of the protein or chemical molecule in the downstream stage.

 7. What are the advantages of molecular diagnostics over conventional methods? 

Ans. The presence of a pathogen is generally suspected using traditional approaches only when the pathogen has caused a clinical sign. By this point, the pathogen's concentration in the body has risen to dangerous levels, although molecular diagnostics may identify a small amount of pathogen via PCR amplification.

8. What are genetically modified organisms? Name two factors on which their behavior depends?

Ans. Genetically modified organisms, often known as transgenic organisms, are organisms whose genes have been manipulated. The following are the two factors that influence their behavior: i) appropriate insertion of the gene of interest. ii) Proper harvesting of genetically modified organisms in order to obtain the intended outcome.

9. What do you mean by “Biopiracy” Give an example? 

Ans: Biopiracy is defined as the use of bio-resources by multinational corporations and other organizations without proper authorization from the countries and people concerned. For example, Basmati rice grown in India is known for its distinct flavor and aroma, but Basmati rice was patented by an American company under a US patent.

10. What are transgenic Bacteria? Illustrate using any one example? 

Ans. Transgenic bacteria are bacteria that have had genes of interest (i.e. foreign DNA fragments) introduced into their plasmid. For example, when two DNA sequences A and B chains of insulin are introduced into the plasmid of this bacteria, it is called transgenic bacteria and begins to produce insulin chains.

11. Give any two examples of products, how transgenic animals can be used to produce biological compounds? 

Ans. Transgenic animals can be used to produce many biological compounds. For example:

1. Alpha-1-antitrypsin, which is a protein used to cure emphysema.

2. Alpha-lactalbumin-rich, protein-rich milk for human babies that is more nutritionally balanced.

12. How is autoradiography used to detect a mutated gene? 

Ans: In a clone of cells, a single-stranded DNA or RNA tagged with a radioactive molecule is allowed to hybridize to its complements DNA before being detected by autoradiography. Because the probe will not be complementary with the mutant gene, therefore, the clone with the altered gene will not appear on photographic film.

13. Why did Bacterial toxins not kill the bacteria but only the insects? 

Ans. Bacillus thuringiensis is not killed by bacterial toxins. Because the poisonous protein exists as an inactive protoxin that, if consumed by an insect, is transformed into an active form of toxin due to the alkaline pH of the stomach, which dissolves the crystal. The activated toxin binds to the surface of midgut epithelial cells & creates pores that cause cell swelling and lysis.

14. Mention any four applications of Biotechnology in the field of Agriculture? 

Ans: Some of the applications of biotechnology in the field of agriculture are given below:

1. To make crops resistant to abiotic conditions such as cold, drought, salt, and heat.

2. To produce pest-resistant crops in order to lessen reliance on chemical pesticides.

3. To improve mineral utilization efficiency by plants.

4. To increase the nutritional value of food, such as Vit – a nutrient-dense golden rice

15. Why does recombinant Insulin produced by genetic engineering need to be processed? 

Ans: Recombinant insulin produced by genetic engineering need to be processed because proinsulin contains an extra C-peptide separate from the chain of insulin, a peptidase enzyme is added to proinsulin to cleave the C-peptide and reconnect the -chain to form active Insulin.

Long Questions and Answers (3 Marks Questions)

1. Some multinational corporations and other organizations exploit bioresources for commercial gain without proper authentication or compensation to relevant authorities.

1. Name the term used for this unauthorized act.

2. Suggest two ways to get rid of this unauthorized activity.

Ans. 

1. Biopiracy

2. 1. There should be equal sharing of the benefits of bioresources by developed and developing countries.

2. Laws should be made to avoid unauthorized usage of the bioresources.

2. The bacterium Bacillus thuringiensis produces a toxic protein called "cry protein". That protein is lethal to certain insects, but not to bacteria.

1. Why does not this toxin kill bacteria? 

2. After consuming this protein, what type of changes occur in the gut of insects?

3. How did humans use this protein for their benefit? 

Ans. 

1. Protoxin is produced in an inactive form. 

2. This protoxin, in the presence of alkaline pH in the intestine of insects. The toxin binds to the surface of the midgut of the insect that induces pore formation, swelling, and cytolysis, eventually leading to death. 

3. Isolation of specific Bt toxin genes from Bacillus thuringiensis and its integration into several crops such as cotton and corn that are pest-resistant to specific insects.

3. The following are incomplete steps representing the production process of nematode-resistant tobacco plants using the RNAi technique. 

(i) Name the deficient steps in proper order.

(ii) RNAi silences the genes at which step?

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 Ans. (i) (b) Spliced mRNA is introduced into tobacco using Agrobacterium as a vector.

 (d) Formation of dsRNA (double-stranded RNA).

 (f) Silencing of specific mRNA of nematode 

 (g) Survival of parasites becomes difficult. 

(ii) RNA interference can silence genes at the translation level.

4. Explain with an example why are transgenic or genetically modified animals created? 

Ans. Genetically modified or transgenic animals are produced for the given purposes: 

1. To be able to study how genes are regulated and how they affect the normal functioning and development of the body. For example, information gained about the biological role of growth factors like Insulin.

2. Understand how genes contribute to the pathogenesis of the disease. 

3. A useful biological compound is produced by introducing a portion of the DNA encoding for that product in another organism. For example, Antitrypsin can be produced using transgenic organisms. This protein is used in the treatment of emphysema. 

4. To test the vaccine safety. For example, the Polio vaccine was tested in the Genetically Modified mouse. 

5. Toxicity level of the drug can also be tested using transgenic animals.

5. Explain how to produce a nematode-resistant transgenic plant. 

 Ans. The nematode named Meloidogyne incognita infects tobacco plants and reduces the yields of that plant. The specific parasite genes are introduced into plants using the Agrobacterium vector. The genes are introduced to produce both sense and antisense RNA. Then the formation of double-stranded RNA (ds RNA) occurs since these two RNAs are complementary. It neutralizes certain nematode RNA by a process called RNA interference, resulting in the inability of the parasite to live in the transformed host. In this way, the plant is protected from pests.

6. What is Cry Protein? Mention the name of the organism that produces the protein. How did the human use this protein for his benefit? 

Ans. A crystalline protein is produced by the soil bacterium named Bacillus thuringiensis which is known as the 'Cry protein'. This protein is toxic to the larvae of insects such as tobacco buds, beetles, and mosquitoes. The cry protein is produced as an inactive protoxin and is converted to an active toxin when ingested by the insect. The intestinal alkaline pH of insects is capable of solubilizing the crystals of cry protein. The binding of the activated form of cry protein to the midgut of insects creates pores in the intestinal epithelial cells, causing cell lysis and then the death of the insect. The gene encoding this protein contains bacteria and is incorporated in the crops to make them insect-resistant.

7. Write a description of the production of human insulin in the genetically modified organism. 

Ans. Human insulin, a protein, is made up of two short polypeptide chains: chain A and B. These chains are linked by disulfide bonds. Insulin is secreted as a precursor hormone or prohormone that is made functional or matured by processing.  The processing of precursor hormone is the removal of another polypeptide called C-peptide present in the precursor hormone to make it functional. The two DNA sequences encoding the chains A and B of human insulin were introduced into the plasmid in Escherichia coli, using genetic engineering that is then used for the formation of insulin protein. The resulting two chains are extracted and joined by creating a disulfide bridge.

8. Compare and distinguish the advantages and disadvantages of the production of genetically modified organisms. 

Ans. 

Advantages of Producing GMOs (Genetically Modified Organisms):

1. Desirable phenotypic traits can be introduced in the crop plants by producing GM crops.

2. A gene involved in the production of a specific protein can be introduced into a GM crop so that these crops produce that specific protein. 

3. New end products of the specific biochemical pathway are synthesized by genetically modified crops. 

4. The expression of existing unique genes can also be prevented using genetically modified crops. 

GMOs (Genetically Modified Organisms) Production Disadvantages: 

1. Transformed or genetically modified (GM) crops can endanger wild or native species. 

2. GM crops may supply allergens that can cause health problems. 

3. GM crops can damage the natural environment.

9. What do you understand by RNA-silencing? How can this strategy be used to make plants that are resistant to pests? 

Ans. RNA silencing is a method by which complementary ds RNA molecules bind to the specific mRNA and interfere with their translation, silencing, or inactivating those specific mRNAs. The infection of the roots of tobacco plants bearing the nematode Meloidogyne incognita can be prevented using this strategy. This strategy results in the formation of a dsRNA complementary to a specific mRNA. Viruses can be used as the source of this complementary RNA.  These RNAs can be introduced by infection by a virus with the RNA genome. A nematode-specific gene was introduced into a host plant using an Agrobacterium vector. DNA introduction led to the production of both sense and anti-dense RNA in the host cells. The two RNAs were complementary to each other and formed double-stranded RNA to initiate RNAi & to silence a particular nematode mRNA. The result was that the organism was unable to survive in the transformed host.

10. What steps are involved in the synthesis of genetically engineered insulin? 

Ans. The steps involved in the production of genetically engineered insulin are given below: 

1. RNA is extracted from the beta-cells of Islet of Langerhans in the pancreas to synthesize insulin. 

2. Single-stranded DNA complementary to mRNA is synthesized with the help of the enzyme reverse transcriptase. Then the second chain of DNA complementary to the first DNA sequence is synthesized with the help of enzyme DNA polymerase. 

3. Both the replicated DNA strands are joined with the plasmid using a terminal transferase enzyme. 

4. The enzyme named ligase is used to anneal both ends of the DNA. In this way, the ends of the plasmid and inserted DNA are sealed to form a new circular plasmid. This is a recombinant DNA molecule. 

5. In the next step, this recombinant DNA is inoculated into new E.coli bacterial cells, digested with restriction enzymes, and inserted into the bacterial gene. 

6. After adequate gene expression, the germ cells from both cultures are lysed with the appropriate chemical. The insulin portion is then separated from the enzyme using cyanogen bromide.

Very Long Questions and Answers (5 Marks Questions)

1. To a 4-year-old patient, clinical gene therapy is given for an enzyme, which is important for the immune system to function. 

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After observing the treatment flow chart, answer the following questions. 

1. Complete the missing steps (B) and (D) in the given flowchart. 

2. Identify the disease to be treated. 

3. Why doesn't the above method have a perfect solution to your problem? 

4. Explain how the scientists have developed a way to cure this disease forever. 

Ans.

1. Step (B): Lymphocytes proliferate in the culture medium. 

Step (D): Genetically engineered lymphocytes are injected into patients. 

2. Deficiency of Adenosine deaminase (ADA) enzyme. 

3. Genetically manipulated lymphocytes are not immortal, so the patients need to be infused with cells regularly. 

4. Genes isolated from bone marrow cells that produce ADA can be a permanent treatment when introduced into cells at the early embryonic stage.

2. Explain the steps a, b, c, d, and e shown in the given figure. In the given figure, Agrobacterium is used for the production of transformed crops. 

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Ans. Step (a) Remove the plasmid and then cleave it using the restriction endonuclease enzyme. 

Step (b) Isolation of the gene of interest from other organisms and amplify it using PCR.

Step (c) Insert the new gene into a plasmid.

Step (d) Put back the plasmid into Agrobacterium. 

Step (e) Agrobacterium-based transformation.

3. In the picture shown below, shape (A) and shape (B) indicate other forms of the peptide hormone secreted by the mammalian pancreas. 

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1. What type of bond is present between hormonal chains? 

2. What are the shape (A) and shape (B)? How are these shapes are different from each other? 

3. Explain how rDNA technology was used to produce this hormone by the US company Eli Lilly. 

Ans. 

1. A disulfide bond is present between the two hormonal chains.

2. Shape (A) is the proinsulin form whereas Shape (B) is the mature or active form of insulin. Proinsulin contains an additional stretch called C-peptide, which is not found in mature insulin. 

3. Two DNA sequences corresponding to the A and B peptide chains of human insulin were prepared by Eli Lilly company which were then introduced into the plasmid E. coli to generate insulin chains. Chains A and B were created and extracted separately and joined by making an insulin-forming disulfide bond to produce insulin protein. 

4. Define Gene Therapy. Can you explain it using an example of Adenosine deaminase (ADA) deficiency? 

Ans. A collection of methods that helps the correction of gene deletions or gene defects is known as gene therapy. 

This method involves inserting a gene into an individual's cells and tissues to address a specific genetic disorder. This involves transferring the normal gene to an individual or embryo, replacing the defective mutant allele of the gene. It is used as a viral vector to attack the host cell and introduce the genetic material into the host. 

For example, adenosine deaminase (ADA) deficiency can be cured in some children through bone marrow transplantation, but gene therapy does not. Lymphocytes proliferate in culture and functional ADA, and cDNA is introduced into these lymphocytes. If so, these lymphocytes are transferred to the patient's body and the patient needs an injection of such genetically engineered lymphocytes.

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Conclusion

Vedantu's Important Questions for CBSE Class 12 Biology Chapter 12 "Biotechnology and Its Applications" provide a valuable resource for students studying this topic. These questions are carefully curated to cover the key concepts and principles of biotechnology, ensuring that students have a comprehensive understanding of the subject. By practicing these questions, students can enhance their problem-solving skills and gain confidence in tackling examination questions. Vedantu's selection of important questions also helps students prioritize their study areas and focus on the most relevant topics. Overall, Vedantu's Important Questions for CBSE Class 12 Biology Chapter 12 serve as a beneficial tool for students to consolidate their knowledge and excel in their examinations.