CBSE Class 12 Biology – Chapter 12 Biotechnology and Its Applications | MCQs with Answers & Explanations (NCERT)

Course, Unit & 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: Multiple Choice Questions (MCQs)
• Exam Relevance: CBSE Class 12 Board Examination

CBSE Class 12 Biology Chapter 12 – Biotechnology and Its Applications | 50 MCQs with Answers & Explanations (NCERT)

SECTION A: Biotechnology in Agriculture (MCQs 1–10)

Q1. The primary objective of biotechnology in agriculture is to:
A. Increase pesticide usage
B. Improve crop yield and quality
C. Replace traditional farming
D. Reduce food consumption

Correct Answer: B
Explanation: Biotechnology aims to enhance yield, nutritional quality, and resistance to stress while reducing chemical inputs, as stated in NCERT.

Q2. Which of the following is an abiotic stress addressed using biotechnology?
A. Pest attack
B. Fungal disease
C. Drought
D. Weeds

Correct Answer: C
Explanation: Abiotic stresses include drought, salinity, and temperature extremes, managed by introducing stress-tolerant genes.

Q3. Biofortification refers to:
A. Pest control in crops
B. Nutritional enhancement of crops
C. Increasing shelf life
D. Weed resistance

Correct Answer: B
Explanation: Biofortification improves vitamin, mineral, or protein content of crops using biotechnology.

Q4. Recombinant DNA technology helps agriculture by:
A. Destroying harmful genes
B. Introducing desirable genes
C. Preventing pollination
D. Eliminating biodiversity

Correct Answer: B
Explanation: Recombinant DNA technology allows insertion of beneficial genes into crop plants.

Q5. Which crop is a commonly grown GM crop in India?
A. GM rice
B. Bt cotton
C. GM wheat
D. Golden maize

Correct Answer: B
Explanation: Bt cotton is the only GM crop commercially grown in India.

Q6. Reduction in chemical pesticide use results in:
A. Soil infertility
B. Environmental pollution
C. Environmental safety
D. Lower crop yield

Correct Answer: C
Explanation: Reduced pesticide use lowers soil and water pollution, promoting sustainability.

Q7. Post-harvest losses can be reduced by:
A. Genetic modification
B. Over-irrigation
C. Excess fertilizers
D. Manual harvesting

Correct Answer: A
Explanation: GM crops may have improved shelf life and resistance to spoilage.

Q8. Which of the following is NOT a goal of agricultural biotechnology?
A. Pest resistance
B. Biofortification
C. Increased pollution
D. Stress tolerance

Correct Answer: C
Explanation: Biotechnology aims to reduce pollution, not increase it.

Q9. GM crops help farmers mainly by:
A. Increasing production cost
B. Reducing crop yield
C. Minimizing crop loss
D. Eliminating all pests

Correct Answer: C
Explanation: Pest-resistant crops reduce losses and improve yield stability.

Q10. Sustainable agriculture emphasizes:
A. Maximum chemical input
B. High pesticide dependence
C. Environmental protection
D. Genetic erosion

Correct Answer: C
Explanation: Biotechnology supports sustainability by minimizing environmental damage.

SECTION B: Genetically Modified Organisms (GMOs) (MCQs 11–18)

Q11. GMOs are produced using:
A. Hybridization
B. Cloning
C. Recombinant DNA technology
D. Tissue culture

Correct Answer: C
Explanation: Genetic engineering alters DNA using recombinant techniques.

Q12. A major concern with GM crops is:
A. Increased yield
B. Gene flow
C. Biofortification
D. Pest resistance

Correct Answer: B
Explanation: Gene flow may transfer GM traits to wild relatives.

Q13. Biosafety testing ensures:
A. Higher yield
B. Farmer profit
C. Human and environmental safety
D. Faster growth

Correct Answer: C
Explanation: Safety testing prevents adverse ecological and health effects.

Q14. Which is a benefit of GM food crops?
A. Reduced nutrition
B. Increased pesticide use
C. Improved nutritional quality
D. Soil degradation

Correct Answer: C
Explanation: GM crops may be nutritionally enhanced through biofortification.

Q15. GMOs are approved for commercial use after:
A. Field trials only
B. Biosafety clearance
C. Farmer approval
D. Public voting

Correct Answer: B
Explanation: Regulatory and biosafety evaluations are mandatory.

Q16. Transfer of GM genes to wild species occurs through:
A. Mutation
B. Pollination
C. Conjugation
D. Transduction

Correct Answer: B
Explanation: Pollination can transfer genes between related plant species.

Q17. GM crops reduce pesticide dependence because they:
A. Grow faster
B. Kill pests internally
C. Avoid insect contact
D. Repel insects physically

Correct Answer: B
Explanation: Insecticidal proteins produced by plants kill pests internally.

Q18. GM crops must be regulated to:
A. Increase profits
B. Prevent misuse
C. Avoid ethical issues
D. Ensure biosafety

Correct Answer: D
Explanation: Regulation ensures safe use for humans and environment.

SECTION C: Bt Crops (MCQs 19–28)

Q19. Bt crops derive their insect resistance from:
A. Virus
B. Fungus
C. Bacterium
D. Algae

Correct Answer: C
Explanation: Bt toxin genes come from Bacillus thuringiensis.

Q20. Bt toxin is toxic to insects because:
A. It blocks respiration
B. It damages gut lining
C. It stops feeding
D. It affects nerves

Correct Answer: B
Explanation: Activated toxin binds to gut epithelial cells, causing lysis.

Q21. Bt toxin remains inactive in plants as:
A. Active toxin
B. Protoxin
C. Enzyme
D. Hormone

Correct Answer: B
Explanation: Protoxin is activated only inside insect gut.

Q22. Bt cotton is mainly resistant to:
A. Aphids
B. Bollworms
C. Locusts
D. Termites

Correct Answer: B
Explanation: Bollworms are the primary target pests of Bt cotton.

Q23. Bt toxin is harmless to humans because:
A. Humans lack stomach
B. Toxin is neutralized
C. Human gut is acidic
D. Humans lack DNA

Correct Answer: C
Explanation: Bt toxin is activated only in alkaline insect gut.

Q24. Cry gene codes for:
A. Antibiotic resistance
B. Insecticidal protein
C. Herbicide tolerance
D. Stress resistance

Correct Answer: B
Explanation: Cry proteins kill specific insect pests.

Q25. Bt crops reduce environmental pollution by:
A. Increasing yield
B. Reducing pesticide sprays
C. Increasing fertilizers
D. Eliminating insects

Correct Answer: B
Explanation: Fewer chemical sprays reduce soil and water contamination.

Q26. Bt technology is an example of:
A. Chemical pest control
B. Mechanical control
C. Biological pest control
D. Physical control

Correct Answer: C
Explanation: It uses biological toxins encoded genetically.

Q27. Bt toxin targets insects with:
A. Acidic gut
B. Neutral gut
C. Alkaline gut
D. No gut

Correct Answer: C
Explanation: Alkaline pH activates Bt protoxin.

Q28. Bt crops are considered eco-friendly because they:
A. Kill all insects
B. Affect non-target species
C. Are pest-specific
D. Reduce yield

Correct Answer: C
Explanation: Specificity prevents harm to beneficial organisms.

SECTION D: RNA Interference (MCQs 29–34)

Q29. RNA interference involves:
A. DNA replication
B. mRNA silencing
C. Protein synthesis
D. Cell division

Correct Answer: B
Explanation: RNAi blocks translation by degrading mRNA.

Q30. RNAi is triggered by:
A. Single-stranded RNA
B. Double-stranded RNA
C. DNA fragments
D. Proteins

Correct Answer: B
Explanation: dsRNA initiates RNA interference.

Q31. siRNA stands for:
A. Small internal RNA
B. Short inhibitory RNA
C. Small interfering RNA
D. Silent RNA

Correct Answer: C
Explanation: siRNAs guide mRNA degradation.

Q32. RNAi technology in plants is used to:
A. Increase growth
B. Kill bacteria
C. Control nematodes
D. Improve photosynthesis

Correct Answer: C
Explanation: RNAi is used to develop nematode-resistant plants.

Q33. RNAi is highly specific because:
A. It affects all genes
B. It targets complementary mRNA
C. It degrades DNA
D. It blocks transcription

Correct Answer: B
Explanation: Only matching mRNA sequences are degraded.

Q34. RNAi does NOT affect:
A. Target gene
B. Non-target genes
C. Protein synthesis
D. mRNA stability

Correct Answer: B
Explanation: RNAi avoids non-target gene effects.

SECTION E: Biotechnology in Medicine & Gene Therapy (MCQs 35–50)

Q35. The first recombinant therapeutic protein was:
A. Insulin
B. Interferon
C. Growth hormone
D. Vaccine

Correct Answer: A
Explanation: Human insulin was first produced using rDNA technology.

Q36. Recombinant insulin is preferred because it:
A. Is cheaper only
B. Is identical to human insulin
C. Works slower
D. Is plant-derived

Correct Answer: B
Explanation: It avoids allergic reactions caused by animal insulin.

Q37. Interferons are used to treat:
A. Bacterial diseases
B. Viral infections
C. Fungal diseases
D. Genetic disorders

Correct Answer: B
Explanation: Interferons inhibit viral replication.

Q38. Gene therapy aims to:
A. Remove genes
B. Correct defective genes
C. Clone individuals
D. Increase mutations

Correct Answer: B
Explanation: Functional genes replace defective ones.

Q39. ADA deficiency affects:
A. Digestive system
B. Nervous system
C. Immune system
D. Circulatory system

Correct Answer: C
Explanation: ADA deficiency leads to immune dysfunction.

Q40. Somatic gene therapy affects:
A. Germ cells
B. Body cells
C. Offspring
D. DNA permanently

Correct Answer: B
Explanation: Changes are not inherited.

Q41. Germline gene therapy is avoided due to:
A. Technical difficulty
B. Ethical issues
C. Low success
D. Cost

Correct Answer: B
Explanation: It affects future generations.

Q42. Transgenic animals are used for:
A. Food only
B. Disease research
C. Farming only
D. Pollution control

Correct Answer: B
Explanation: They model human diseases.

Q43. Pharming involves:
A. Drug testing
B. Protein production
C. Gene silencing
D. Vaccine delivery

Correct Answer: B
Explanation: Pharmaceuticals are produced in transgenic animals.

Q44. Human proteins in transgenic animals are usually obtained from:
A. Blood
B. Urine
C. Milk
D. Saliva

Correct Answer: C
Explanation: Milk is commonly used for protein extraction.

Q45. Biopatenting refers to:
A. Gene silencing
B. Patent of biological products
C. Animal cloning
D. Drug testing

Correct Answer: B
Explanation: It grants ownership rights over biotech products.

Q46. Unauthorized use of biological resources is called:
A. Bioethics
B. Biopiracy
C. Biopatent
D. Biosecurity

Correct Answer: B
Explanation: Biopiracy exploits native resources without consent.

Q47. Ethical issues in biotechnology arise due to:
A. Scientific errors
B. Ownership and safety concerns
C. Lack of technology
D. Farmer resistance

Correct Answer: B
Explanation: Ethics ensure fair and safe use.

Q48. Biosafety regulations are essential to:
A. Increase yield
B. Promote GMOs
C. Protect environment
D. Speed up approvals

Correct Answer: C
Explanation: They prevent ecological and health risks.

Q49. Transgenic mice are commonly used to study:
A. Photosynthesis
B. Cancer
C. Respiration
D. Digestion

Correct Answer: B
Explanation: They help understand cancer development.

Q50. Biotechnology applications must be regulated to ensure:
A. Profit
B. Speed
C. Safety and ethics
D. Popularity

Correct Answer: C
Explanation: Regulation ensures responsible and ethical use.

🎯 Targeting Exams

This MCQ set is useful for preparation of:

• CBSE Class 12 Board Examination

• CBSE Term-wise & Annual Assessments

• School Unit Tests & Pre-Board Exams

• NEET (Biology – Biotechnology basics)

• CUET (UG) – Biology domain

• Competitive medical entrance foundation exams

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