Important Questions Class 12 Biology Chapter 10 Biotechnology and Its Applications With Answers

Biotechnology uses living organisms, cells, enzymes, and genetic techniques to produce useful biological products. Insulin, Bt cotton, gene therapy, molecular diagnosis, and transgenic animals are common biotechnology applications.

Biotechnology becomes easier when students connect genetically modified organisms with real uses in agriculture and medicine. Important Questions Class 12 Biology Chapter 10 help students revise Biotechnology and Its Applications for CBSE 2026-27 board exams, school tests, and pre-board papers. NCERT Chapter 10 explains GM crops, Bt cotton, RNA interference, recombinant insulin, gene therapy, molecular diagnosis, transgenic animals, ethical issues, patents, and biopiracy. These topics often appear as 1-mark definitions, 2-mark reasoning answers, 3-mark application questions, and 5-mark process-based answers.

Key Takeaways

• Biotechnology Applications: Biotechnology supports agriculture, medicine, diagnostics, bioremediation, waste treatment, and processed food production.
• GM Crops: Bt cotton contains Bt toxin genes from Bacillus thuringiensis to resist specific insect pests.
• Medical Biotechnology: Recombinant DNA technology enables safe production of insulin, molecular diagnosis, and gene therapy.
• Ethical Regulation: GEAC evaluates GM research and the safety of releasing GM organisms for public use in India.

Important Questions Class 12 Biology Chapter 10 Structure 2026-27

Important Questions Class 12 Biology Chapter 10 for CBSE 2026-27

Biotechnology questions usually test how a biological principle becomes a useful product or method. CBSE and NCERT-based state boards often ask this chapter through examples like Bt cotton, ADA deficiency, insulin, and biopiracy.

1. What are the main applications of biotechnology?

The main applications of biotechnology include agriculture, medicine, diagnostics, processed food, bioremediation, waste treatment, and energy production. These applications use genetically modified microbes, plants, fungi, and animals.

1. Agriculture uses biotechnology for pest-resistant crops.
2. Medicine uses biotechnology for insulin and gene therapy.
3. Diagnostics uses PCR and ELISA for early disease detection.
4. Industry uses biotechnology for biological products.

Final answer:
Biotechnology improves food production, healthcare, and industrial processes.

2. What are the three critical research areas of biotechnology?

The three critical research areas of biotechnology are improved catalysts, optimal conditions, and downstream processing. These areas help produce useful biological products at industrial scale.

1. Improved catalyst: microbe or pure enzyme.
2. Optimal conditions: engineering support for catalyst action.
3. Downstream processing: purification of protein or organic compound.

Final fact:
Industrial biotechnology depends on all three areas.

3. Which three options can increase food production?

The three options for increasing food production are agrochemical agriculture, organic agriculture, and genetically engineered crop-based agriculture.

1. Agrochemical agriculture uses fertilisers and pesticides.
2. Organic agriculture reduces synthetic chemical use.
3. Genetically engineered crops use gene manipulation.

Final fact:
Genetically engineered crops reduce some limits of conventional breeding.

Biotechnology and Its Applications Class 12 Important Questions on Agriculture

Agricultural biotechnology focuses on rapid plant propagation, pest resistance, and improved crop traits. Indian school exams often connect this section with tissue culture, Bt cotton, RNA interference, and GM crops.

4. What is tissue culture in plants?

Tissue culture is the growth of plant cells, tissues, or organs under sterile conditions on a nutrient medium. It can regenerate a whole plant from an explant.

1. An explant is a plant part used for culture.
2. The medium contains sucrose, salts, vitamins, amino acids, and growth regulators.
3. Auxins and cytokinins support growth and regeneration.

Final fact:
Tissue culture uses the totipotency of plant cells.

5. What is totipotency?

Totipotency is the capacity of a plant cell or explant to regenerate into a complete plant. It forms the basis of tissue culture.

1. A plant part is removed as an explant.
2. It grows under sterile in vitro conditions.
3. A complete plant develops from the cells.

Example:
Tomato, banana, and apple can be produced through tissue culture.

6. What is micropropagation?

Micropropagation is the production of thousands of plants through tissue culture in a short time. The plants produced are genetically identical to the parent plant.

1. Explants grow in nutrient media.
2. Many plantlets develop quickly.
3. Each plantlet has the same genetic makeup.

Final fact:
Plants produced through micropropagation are called somaclones.

7. Why is meristem culture used to obtain virus-free plants?

Meristem culture gives virus-free plants because apical and axillary meristems are usually free from virus infection. Diseased plants can produce healthy plantlets through this method.

1. A virus-infected plant may still have virus-free meristem tissue.
2. The meristem is removed and grown in vitro.
3. The regenerated plant becomes healthy.

Examples:
Banana, sugarcane, and potato can be recovered through meristem culture.

8. What is somatic hybridisation?

Somatic hybridisation is the fusion of isolated protoplasts from two plant varieties to form a somatic hybrid. It combines desirable traits from different plants.

1. Cell walls are removed to obtain protoplasts.
2. Protoplasts from two varieties are fused.
3. The hybrid protoplast grows into a new plant.

Example:
Tomato and potato protoplasts produced pomato.

Biotechnology Class 12 Questions With Answers on GM Crops

Genetically modified crops carry altered genes that give useful traits. CBSE 2026-27 questions often ask benefits, examples, and pest-resistance mechanisms.

9. What are genetically modified organisms?

Genetically modified organisms are plants, animals, fungi, or bacteria whose genes have been altered by manipulation. They are also called GMOs.

1. A selected gene is introduced or modified.
2. The organism expresses a new trait.
3. The trait may improve yield, resistance, or nutrition.

Examples:
Bt cotton and golden rice are GM crops.

10. Write any five benefits of genetically modified plants.

GM plants help increase crop tolerance, reduce pesticide reliance, and improve food value. They also support industrial and agricultural needs.

Benefits:

1. Tolerance to cold, drought, salt, and heat.
2. Resistance against pests.
3. Reduced post-harvest losses.
4. Better mineral-use efficiency.
5. Improved nutritional value.

Example:
Golden rice is enriched with Vitamin A.

11. What is Bt cotton?

Bt cotton is a genetically modified cotton plant that contains Bt toxin genes from Bacillus thuringiensis. It protects cotton from specific insect pests.

1. Bt toxin genes are isolated from Bacillus thuringiensis.
2. These genes are inserted into cotton plants.
3. The plant produces insecticidal protein.
4. The target insect dies after feeding on the plant.

Final fact:
Bt cotton reduces the need for chemical insecticides.

12. Why does Bt toxin not kill Bacillus thuringiensis?

Bt toxin does not kill Bacillus thuringiensis because it exists as an inactive protoxin inside the bacterium. It becomes active only in the insect gut.

1. Bt crystals contain inactive protoxin.
2. The insect ingests the inactive toxin.
3. Alkaline pH in the insect gut solubilises the crystals.
4. The toxin becomes active and damages midgut cells.

Final answer:
Bt toxin becomes harmful only after activation in the insect gut.

13. How does Bt toxin kill insects?

Bt toxin kills insects by binding to midgut epithelial cells and creating pores. These pores cause cell swelling, lysis, and death.

Process:

1. Insect eats Bt toxin crystals.
2. Alkaline gut pH activates protoxin.
3. Active toxin binds to midgut epithelial cells.
4. Pores form in the cell membrane.
5. Cells swell and lyse.

Final result:
The insect dies after gut damage.

14. Which cry genes control cotton bollworms and corn borer?

cryIAc and cryIIAb control cotton bollworms, while cryIAb controls corn borer. Bt toxin genes are insect-group specific.

1. cryIAc: cotton bollworms.
2. cryIIAb: cotton bollworms.
3. cryIAb: corn borer.

Final fact:
The selected cry gene depends on the crop and target pest.

Bt Cotton Class 12 Biology Questions and RNA Interference

Bt cotton and RNA interference show how biotechnology protects crops without heavy chemical pesticide use. These topics fit 3-mark and 5-mark CBSE application-based answers.

15. What is RNA interference Class 12?

RNA interference is a cellular defence method that silences a specific mRNA using complementary double-stranded RNA. It prevents translation of the target mRNA.

1. Complementary dsRNA binds to specific mRNA.
2. The mRNA gets silenced.
3. The protein does not form.
4. The target organism cannot survive properly.

Final fact:
RNAi occurs in all eukaryotic organisms.

16. How does RNA interference protect tobacco plants from nematodes?

RNA interference protects tobacco plants by silencing essential mRNA in the nematode Meloidogyne incognita. The parasite cannot survive in the transgenic host.

Steps:

1. Nematode-specific genes enter the plant through Agrobacterium vectors.
2. The plant produces sense and antisense RNA.
3. These RNAs form double-stranded RNA.
4. dsRNA triggers RNA interference.
5. Nematode mRNA gets silenced.

Final result:
The transgenic plant resists nematode infestation.

17. Why are Agrobacterium vectors used in RNAi-based pest resistance?

Agrobacterium vectors introduce nematode-specific genes into host plant cells. These genes help the plant form dsRNA against nematode mRNA.

1. Agrobacterium transfers selected DNA into the plant.
2. The inserted DNA produces sense and antisense RNA.
3. Complementary RNA strands form dsRNA.
4. dsRNA initiates gene silencing.

Final fact:
Agrobacterium acts as a gene delivery vector.

Genetically Engineered Insulin Class 12 Important Questions

Medical biotechnology made human insulin safer and more reliable than animal-derived insulin. CBSE questions often ask proinsulin structure, C-peptide removal, and recombinant insulin production.

18. Why was animal insulin replaced by genetically engineered insulin?

Animal insulin was replaced because it caused allergies or immune reactions in some patients. Genetically engineered insulin matches human insulin.

1. Earlier insulin came from slaughtered cattle and pigs.
2. Animal insulin acted as a foreign protein in some patients.
3. Recombinant DNA technology produced human insulin in bacteria.

Final fact:
Recombinant insulin reduces unwanted immune reactions.

19. What is the structure of mature human insulin?

Mature human insulin has two short polypeptide chains called chain A and chain B. These chains remain linked by disulphide bridges.

1. Chain A forms one insulin polypeptide chain.
2. Chain B forms the second insulin polypeptide chain.
3. Disulphide bridges connect both chains.
4. The C peptide is absent in mature insulin.

Final answer:
Mature insulin contains A and B chains linked by disulphide bonds.

20. How did Eli Lilly produce human insulin using E. coli?

Eli Lilly produced human insulin by separately making A and B chains in E. coli and joining them through disulphide bonds.

Steps:

1. DNA sequences for insulin chains A and B were prepared.
2. These sequences were inserted into E. coli plasmids.
3. E. coli produced A and B chains separately.
4. The chains were extracted.
5. Disulphide bonds joined them to form insulin.

Final fact:
This method produced mature human insulin in 1983.

21. Why is C peptide absent in mature insulin?

C peptide is absent in mature insulin because it gets removed during proinsulin maturation. Proinsulin contains A chain, B chain, and C peptide.

1. Human insulin first forms as proinsulin.
2. Proinsulin has an extra C peptide.
3. Maturation removes the C peptide.
4. A and B chains remain connected by disulphide bridges.

Final fact:
C peptide is present in proinsulin but absent in mature insulin.

Gene Therapy Class 12 Biology and ADA Deficiency

Gene therapy treats genetic defects by inserting a functional gene into patient cells. ADA deficiency is the most important NCERT example for CBSE 2026-27.

22. What is gene therapy?

Gene therapy is a collection of methods that corrects a gene defect diagnosed in a child or embryo. It introduces a functional gene into cells or tissues.

1. A defective gene causes a disease.
2. A normal gene enters the patient’s cells.
3. The normal gene compensates for the faulty gene.

Final fact:
Gene therapy aims to treat hereditary disorders.

23. What is ADA deficiency?

ADA deficiency is a genetic disorder caused by deletion of the gene for adenosine deaminase. This enzyme is essential for immune system function.

1. ADA stands for adenosine deaminase.
2. ADA supports proper immune function.
3. ADA deficiency weakens immunity.
4. The disorder can be treated by gene therapy.

Final answer:
ADA deficiency affects immune system function.

24. Explain ADA Deficiency Gene Therapy Class 12.

ADA deficiency gene therapy introduces functional ADA cDNA into the patient’s lymphocytes using a retroviral vector. These modified lymphocytes return to the patient.

Steps:

1. Lymphocytes are taken from the patient’s blood.
2. They are grown in culture outside the body.
3. Functional ADA cDNA enters lymphocytes using a retroviral vector.
4. Genetically engineered lymphocytes return to the patient.
5. Periodic infusion is needed because these cells are not immortal.

Final fact:
Early embryonic gene transfer could provide a permanent cure.

25. Why is enzyme replacement therapy not a complete cure for ADA deficiency?

Enzyme replacement therapy is not a complete cure because functional ADA must be given repeatedly by injection. It does not permanently correct the defective gene.

1. The patient receives functional ADA enzyme.
2. The treatment supports immune function temporarily.
3. The defective gene remains unchanged.
4. Regular treatment becomes necessary.

Final fact:
Gene correction offers a stronger curative approach.

Molecular Diagnosis Class 12 Biology Questions

Molecular diagnosis detects disease before symptoms become severe. NCERT highlights PCR, radioactive probes, autoradiography, and ELISA as key diagnostic tools.

26. Why are molecular diagnosis methods useful?

Molecular diagnosis methods are useful because they detect diseases at an early stage. Conventional tests often detect disease only after symptoms appear.

1. Pathogens may remain low before symptoms.
2. PCR can amplify small amounts of nucleic acid.
3. ELISA detects antigens or antibodies.
4. DNA probes detect gene mutations.

Final fact:
Early diagnosis improves treatment planning.

27. How does PCR help in disease diagnosis?

PCR helps diagnosis by amplifying very small amounts of DNA or RNA from pathogens or mutated genes. It helps detect disease before visible symptoms.

Applications:

1. Detection of HIV in suspected AIDS patients.
2. Detection of mutations in suspected cancer patients.
3. Identification of genetic disorders.

Final answer:
PCR detects low pathogen or mutation levels through nucleic acid amplification.

28. What is ELISA?

ELISA is a diagnostic technique based on antigen-antibody interaction. It detects infection by identifying antigens or antibodies.

1. Pathogen antigens may be detected directly.
2. Antibodies produced against the pathogen may be detected.
3. The result indicates infection.

Final fact:
ELISA helps diagnose pathogen-based diseases.

29. How are radioactive probes used in molecular diagnosis?

Radioactive probes detect complementary DNA or RNA sequences in cloned cells. A mutated gene fails to hybridise with the probe.

Steps:

1. A single-stranded DNA or RNA probe is tagged with a radioactive molecule.
2. The probe hybridises with complementary DNA.
3. Autoradiography detects the hybridised region.
4. A mutated gene does not appear on the photographic film.

Final fact:
Probe-based diagnosis identifies gene mutations.

Transgenic Animals Class 12 Questions With Answers

Transgenic animals contain and express foreign genes. NCERT gives examples from physiology, disease models, biological products, vaccine testing, and chemical safety testing.

30. What are transgenic animals?

Transgenic animals are animals whose DNA has been manipulated to possess and express an extra foreign gene. They help in research and product development.

Examples:

1. Transgenic rats
2. Transgenic rabbits
3. Transgenic pigs
4. Transgenic sheep
5. Transgenic cows
6. Transgenic fish
7. Transgenic mice

Final fact:
Over 95 percent of existing transgenic animals are mice.

31. Why are transgenic animals produced?

Transgenic animals are produced to study genes, diseases, biological products, vaccine safety, and chemical safety. They help scientists test biological effects.

Uses:

1. Study of normal physiology and development.
2. Study of human diseases.
3. Production of biological products.
4. Vaccine safety testing.
5. Toxicity testing.

Final fact:
Transgenic animals support medical and biological research.

32. How do transgenic animals help in studying diseases?

Transgenic animals help disease research by acting as models for human diseases. They show how genes contribute to disease development.

Examples of disease models:

1. Cancer
2. Cystic fibrosis
3. Rheumatoid arthritis
4. Alzheimer’s disease

Final fact:
Disease models help test new treatments.

33. What was special about Rosie, the transgenic cow?

Rosie was the first transgenic cow that produced human protein-enriched milk in 1997. The milk contained human alpha-lactalbumin.

1. Rosie’s milk had 2.4 grams of human protein per litre.
2. The protein was human alpha-lactalbumin.
3. The milk was more nutritionally balanced for human babies than natural cow milk.

Final answer:
Rosie produced human protein-enriched milk.

Biopiracy Class 12 Biology and Ethical Issues

Biotechnology needs ethical control because genetic modification can affect ecosystems, farmers, patients, and traditional knowledge. India uses regulatory bodies and patent laws to address these issues.

34. What is GEAC Class 12 Biology?

GEAC is the Genetic Engineering Approval Committee set up by the Indian Government. It evaluates GM research and GM organism safety.

Functions:

1. It checks the validity of GM research.
2. It evaluates the safety of GM organisms.
3. It decides whether GM organisms can enter public services.

Final fact:
GEAC regulates genetic engineering activities in India.

35. What is biopiracy?

Biopiracy is the unauthorised use of bio-resources by companies or organisations without proper permission or compensation. It often affects biodiversity-rich countries.

1. Developing countries have rich biodiversity.
2. They also have traditional knowledge.
3. Companies may use these resources without fair benefit sharing.

Final answer:
Biopiracy exploits biological resources and traditional knowledge.

36. Why is the Basmati rice patent issue important?

The Basmati rice patent issue is important because it involved a crop linked with India’s agricultural history and traditional knowledge. India has rich Basmati diversity.

1. India has many rice varieties.
2. Basmati has unique aroma and flavour.
3. A foreign company claimed a new Basmati variety.
4. The variety came from Indian farmer varieties.

Final fact:
The issue showed the need to protect indigenous bio-resources.

37. Why are ethical standards needed in biotechnology?

Ethical standards are needed because manipulation of living organisms can help or harm life forms. GM organisms may also produce unpredictable ecological effects.

1. Genetic modification changes living systems.
2. Released GM organisms may affect ecosystems.
3. Patents may affect farmers and indigenous communities.
4. Public safety needs proper regulation.

Final fact:
Biotechnology must follow ethical and legal checks.

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