CBSE Class 12 Biology – Chapter 12 Biotechnology and Its Applications | Short Answer Type Questions (NCERT Based)

Course & Examination Details

• Course: CBSE Class XII Biology
• Board: Central Board of Secondary Education
• Unit: IV – Biotechnology
• Chapter: 12 – Biotechnology and Its Applications
• Prescribed By: National Council of Educational Research and Training (NCERT)
• Question Type: Short Answer Type
• Answer Length: 60–80 words
• Exam Relevance: CBSE Class 12 Board Examination

CBSE Class 12 Biology Chapter 12 – Biotechnology and Its Applications | 50 Short Answer Questions (NCERT)

SECTION A: Biotechnology in Agriculture (Q1–Q8)

Q1. Explain the role of biotechnology in improving agricultural productivity.
Ans: Biotechnology improves agricultural productivity by developing genetically modified crops with higher yield, pest resistance, and tolerance to abiotic stresses. It reduces dependency on chemical fertilizers and pesticides, lowers crop losses, and supports sustainable farming practices, as highlighted in NCERT.

Q2. How does genetic modification help in pest management?
Ans: Genetic modification introduces insecticidal genes into plants, enabling them to produce toxins harmful to specific pests. This reduces crop damage, minimizes pesticide usage, and lowers environmental pollution while maintaining crop safety for humans.

Q3. What is biofortification? State its importance.
Ans: Biofortification is the enhancement of nutritional quality of crops using biotechnology. It increases vitamins, minerals, or protein content, helping combat malnutrition and improving public health, especially in developing countries.

Q4. How does biotechnology help in reducing post-harvest losses?
Ans: Biotechnology develops crops with improved shelf life and resistance to spoilage organisms. Such modifications reduce post-harvest losses during storage and transportation, improving food availability.

Q5. Mention two advantages of GM crops.
Ans: GM crops offer increased yield and reduced pesticide use. They also provide resistance to pests and environmental stress, making agriculture more efficient and sustainable.

Q6. What is recombinant DNA technology in agriculture?
Ans: Recombinant DNA technology involves inserting desirable genes into crop plants to improve traits like pest resistance, nutritional quality, and stress tolerance.

Q7. Name one abiotic stress managed through biotechnology. Explain briefly.
Ans: Drought stress is managed by introducing genes that improve water retention and stress tolerance, helping plants survive low-water conditions.

Q8. Why is biotechnology considered environment-friendly in agriculture?
Ans: It reduces chemical pesticide usage, minimizes soil and water pollution, and promotes sustainable crop production.

SECTION B: Genetically Modified Organisms (GMOs) (Q9–Q15)

Q9. Define genetically modified organisms.
Ans: Genetically modified organisms are organisms whose genetic material has been altered using genetic engineering techniques to introduce new traits not present naturally.

Q10. State two benefits of GM food crops.
Ans: GM food crops provide improved nutritional quality and increased resistance to pests, resulting in better yield and food security.

Q11. What is gene flow in GMOs?
Ans: Gene flow is the transfer of modified genes from GM crops to wild relatives through pollination, potentially affecting biodiversity.

Q12. Mention one environmental concern related to GMOs.
Ans: GMOs may affect non-target organisms and disrupt natural ecosystems if not regulated properly.

Q13. Why are GMOs subjected to biosafety testing?
Ans: Biosafety testing ensures that GMOs are safe for human consumption and do not harm the environment.

Q14. How do GM crops reduce chemical pesticide use?
Ans: GM crops produce insecticidal proteins internally, eliminating the need for external pesticide application.

Q15. Name one commercially grown GM crop.
Ans: Bt cotton is a widely grown GM crop in India.

SECTION C: Bt Crops (Q16–Q22)

Q16. What are Bt crops?
Ans: Bt crops are genetically modified plants that produce insecticidal Cry proteins derived from Bacillus thuringiensis to control specific pests.

Q17. Explain the mechanism of action of Bt toxin.
Ans: Bt toxin is produced as an inactive protoxin in plants. In the alkaline insect gut, it becomes active, binds to gut epithelial cells, and causes cell lysis.

Q18. Why is Bt toxin harmless to humans?
Ans: Bt toxin is activated only in the alkaline gut of insects, not in the acidic human digestive system.

Q19. Name the target pest of Bt cotton.
Ans: Bt cotton targets bollworm insects.

Q20. How are Bt crops environmentally safe?
Ans: They are specific to target pests and reduce chemical pesticide usage.

Q21. What is Cry protein?
Ans: Cry protein is an insecticidal protein produced by Bacillus thuringiensis.

Q22. Bt crops represent which type of pest control?
Ans: Biological pest control through genetic engineering.

SECTION D: RNA Interference (RNAi) (Q23–Q27)

Q23. What is RNA interference?
Ans: RNA interference is a natural cellular mechanism that silences specific mRNA molecules, preventing protein synthesis.

Q24. How does double-stranded RNA function in RNAi?
Ans: Double-stranded RNA triggers degradation of complementary mRNA, stopping translation.

Q25. What are siRNAs?
Ans: Small interfering RNAs guide the degradation of specific mRNA during RNA interference.

Q26. Mention one agricultural application of RNAi.
Ans: RNAi is used to develop nematode-resistant crops.

Q27. Why is RNAi considered specific?
Ans: It targets only complementary mRNA sequences.

SECTION E: Biotechnology in Medicine (Q28–Q33)

Q28. How is insulin produced using biotechnology?
Ans: Human insulin is produced by inserting the insulin gene into bacteria, enabling large-scale, pure insulin production.

Q29. Why is recombinant insulin preferred?
Ans: It is free from allergens and identical to human insulin.

Q30. What are interferons?
Ans: Interferons are antiviral proteins produced using recombinant DNA technology.

Q31. State one advantage of recombinant therapeutic proteins.
Ans: They ensure high purity and safety.

Q32. How has biotechnology improved disease diagnosis?
Ans: It enables early detection using molecular techniques.

Q33. Name one hormone produced biotechnologically.
Ans: Human growth hormone.

SECTION F: Gene Therapy (Q34–Q38)

Q34. Define gene therapy.
Ans: Gene therapy involves correcting defective genes by introducing functional genes into patient cells.

Q35. Explain ADA deficiency treatment.
Ans: Functional ADA gene is introduced into patient cells to restore immune function.

Q36. What is somatic gene therapy?
Ans: It involves modification of body cells and is non-heritable.

Q37. Why is germline therapy avoided?
Ans: It affects future generations and raises ethical issues.

Q38. What is the goal of gene therapy?
Ans: To cure genetic disorders at the molecular level.

SECTION G: Transgenic Animals (Q39–Q44)

Q39. Define transgenic animals.
Ans: Animals carrying foreign genes introduced through genetic engineering.

Q40. Why are transgenic animals produced?
Ans: For disease research, drug testing, and protein production.

Q41. Name one transgenic animal used in research.
Ans: Transgenic mice.

Q42. What is pharming?
Ans: Production of pharmaceuticals using transgenic animals.

Q43. How do transgenic animals help in vaccine testing?
Ans: They test vaccine safety before human trials.

Q44. Which fluid is commonly used to extract proteins?
Ans: Milk.

SECTION H: Ethical Issues in Biotechnology (Q45–Q50)

Q45. What is biopatenting?
Ans: Granting patents for biological products developed through biotechnology.

Q46. Define biopiracy.
Ans: Unauthorized exploitation of biological resources.

Q47. Why are ethical regulations necessary?
Ans: To ensure safe and fair use of biotechnology.

Q48. Name one issue related to biopatenting.
Ans: Restricted access to genetic resources.

Q49. Who monitors ethical issues in biotechnology?
Ans: Regulatory authorities and ethics committees.

Q50. Why is biosafety testing important?
Ans: To protect humans and the environment from potential risks.