🧬 Chapter 10: Biotechnology: Biotechnology & Its Applications– Class 12 -- 5 Marks Questions with Answers | NCERT + NEET Focus

 

🌸Chapter 10

Biotechnology: Biotechnology & Its Applications

(5 Marks) 

A. Introduction to Biotechnology (Q1–10)

1.   Explain biotechnology and its importance in modern science.
Answer: Biotechnology is the use of living organisms, their cells, or products to develop useful technologies, products, or processes. It is important because it contributes to:

• Medicine: Production of vaccines, insulin, antibiotics, gene therapy.
• Agriculture: GM crops, pest resistance, biofertilizers.
• Industry: Biofuels, enzymes, biodegradable plastics.
• Environment: Bioremediation, waste management.

2.   Describe the main branches of biotechnology with examples.
Answer:

• Red biotechnology: Healthcare – e.g., production of insulin in E. coli.
• Green biotechnology: Agriculture – e.g., Bt cotton.
• White biotechnology: Industry – e.g., biofuel production using microbes.
• Blue biotechnology: Marine applications – e.g., bioactive compounds from marine algae.

3.   Explain the role of microbes in biotechnology. Give four examples.
Answer: Microbes are used because they grow rapidly, are easy to manipulate, and produce enzymes and metabolites. Examples:

• E. coli: Recombinant insulin
• Saccharomyces cerevisiae: Alcohol production
• Penicillium: Penicillin production
• Rhizobium: Nitrogen fixation in plants

4.   Differentiate between conventional breeding and biotechnological approaches in agriculture.
Answer:
| Aspect | Conventional Breeding | Biotechnology |
|--------|---------------------|---------------|
| Speed | Slow | Fast |
| Precision | Low | High |
| Scope | Within species | Across species |
| Examples | Hybrid varieties | Bt cotton, Golden Rice |

5.   Explain how biotechnology contributes to sustainable development.
Answer: Biotechnology promotes sustainability by:

• Reducing chemical fertilizer use (biofertilizers)
• Producing biofuels instead of fossil fuels
• Cleaning polluted environments (bioremediation)
• Reducing pesticide usage through pest-resistant GM crops

6.   Describe the importance of GMOs in modern agriculture.
Answer: GMOs are crops with foreign genes that confer desired traits:

• Pest resistance (Bt cotton)
• Herbicide tolerance
• Nutritional enhancement (Golden Rice with beta-carotene)
• Faster growth or higher yield

7.   Explain the concept of industrial biotechnology with examples.
Answer: Industrial (white) biotechnology uses microbes and enzymes for large-scale production of useful chemicals and biofuels. Examples:

• Ethanol production from sugar by Saccharomyces cerevisiae
• Citric acid production by Aspergillus niger
• Enzyme production for detergents and food processing

8.   Give four applications of biotechnology in medicine.
Answer:

• Recombinant insulin production for diabetes
• Human growth hormone production
• Gene therapy for SCID or hemophilia
• Vaccine production (Hepatitis B, COVID-19)

9.   Explain blue biotechnology with two examples.
Answer: Blue biotechnology uses marine resources for applications in medicine and industry. Examples:

• Marine algae producing agar for microbiology
• Marine sponges producing bioactive compounds for anticancer drugs

10.                   Describe the importance of biotechnology in environmental management.
Answer: Biotechnology helps in:

• Bioremediation: Microbes degrade oil spills and pollutants
• Waste management: Microbial digestion of organic waste into biogas
• Biofertilizers: Improve soil fertility naturally
• Sustainable agriculture: Reduces chemical use and enhances productivity

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B. Recombinant DNA Technology (Q11–20)

11.                   Explain recombinant DNA technology with diagram and steps.
Answer: Recombinant DNA technology involves combining DNA from two sources. Steps:

12.                   Gene isolation: Identify and extract desired gene

13.                   Insertion into vector: Using restriction enzymes and DNA ligase

14.                   Introduction into host: Transformation into bacteria or yeast

15.                   Selection & screening: Identify successful recombinant cells

16.                   Expression: Host expresses protein for medical or industrial use
(Diagram can depict gene → vector → host → product)

17.                   Describe the role of restriction enzymes and DNA ligase in recombinant DNA technology.
Answer:

• Restriction enzymes: Cut DNA at specific sequences to isolate genes or open vectors.
• DNA ligase: Joins DNA fragments by forming phosphodiester bonds, creating stable recombinant DNA.

13.                   Explain plasmids as vectors and their importance.
Answer: Plasmids are small, circular DNA molecules in bacteria. They replicate independently and carry foreign genes into host cells. Importance: Easy gene insertion, expression, and production of proteins like insulin.

14.                   Describe the production of human insulin using recombinant DNA technology.
Answer:

15.                   Isolate human insulin gene

16.                   Insert into plasmid vector using restriction enzyme and DNA ligase

17.                   Transform plasmid into E. coli

18.                   Bacteria express insulin protein

19.                   Insulin purified for diabetic treatment

20.                   Explain PCR and its significance.
Answer: PCR amplifies a specific DNA sequence using primers, nucleotides, and DNA polymerase. Significance:

• Cloning genes
• Diagnosing genetic disorders
• Forensic identification
• Detection of pathogens

16.                   Explain the role of Agrobacterium tumefaciens in plant genetic engineering.
Answer: A. tumefaciens transfers T-DNA from its Ti plasmid into plant cells. Scientists replace tumor-causing genes with desired genes. The foreign gene integrates into plant genome, producing GM plants.

17.                   Describe the difference between transformation, transduction, and conjugation.
Answer:

• Transformation: Uptake of free DNA from environment
• Transduction: Gene transfer via bacteriophage
• Conjugation: Gene transfer via direct contact using pili

18.                   Explain screening and selection in recombinant DNA technology.
Answer: Screening identifies cells that have incorporated recombinant DNA. Selection uses markers to allow only transformed cells to grow. These ensure that only desired recombinant cells are used for protein production.

19.                   Explain the role of GM plants with one example.
Answer: GM plants carry foreign genes for desirable traits. Example: Bt cotton has insecticidal protein from Bacillus thuringiensis, protecting crops from bollworms.

20.                   Describe gene cloning and its applications.
Answer: Gene cloning produces multiple copies of a gene. Applications:

• Recombinant protein production (insulin, clotting factors)
• Gene therapy
• GMOs production
• Study of gene function

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C. Gene Therapy & Stem Cells (Q21–30)

21.                   Explain gene therapy with examples.
Answer: Gene therapy introduces functional genes into patients’ cells to treat genetic disorders.

• Example 1: SCID treated using retroviral vectors
• Example 2: Hemophilia treated with clotting factor genes

22.                   Describe stem cells and their applications.
Answer: Stem cells are undifferentiated cells capable of self-renewal and differentiation. Applications:

• Regeneration of tissues (heart, nerve, liver)
• Treatment of genetic disorders (thalassemia, leukemia)
• Drug testing and disease modeling

23.                   Differentiate embryonic, adult, and induced pluripotent stem cells.
Answer:
| Type | Source | Potency | Example |
|------|--------|---------|--------|
| Embryonic | Blastocyst | Pluripotent | Embryonic stem cells |
| Adult | Bone marrow, cord | Multipotent | Hematopoietic stem cells |
| iPSCs | Reprogrammed somatic | Pluripotent | iPSCs from fibroblasts |

24.                   Explain somatic cell nuclear transfer with example.
Answer: Nucleus from an adult somatic cell is transferred into an enucleated egg. The egg develops into a clone. Example: Dolly the sheep. Applications: Cloning endangered animals, research, therapeutic cloning.

25.                   Explain transgenic animals and their applications.
Answer: Animals carrying foreign genes. Applications:

• Production of therapeutic proteins (insulin, clotting factors)
• Disease models for research
• Improved agricultural traits

26.                   Describe ethical concerns in gene therapy and stem cell research.
Answer:

• Germline modifications may affect future generations
• Risk of tumor formation
• Moral issues with embryo destruction
• Access and equity concerns

27.                   Explain totipotent, pluripotent, and multipotent stem cells with significance.
Answer:

• Totipotent: Can form all cells + extraembryonic tissues. Significance: Early embryogenesis.
• Pluripotent: Can form almost all body cells. Significance: Tissue regeneration.
• Multipotent: Can form limited cell types. Significance: Adult tissue repair.

28.                   Describe somaclones in plant biotechnology.
Answer: Somaclones are plants derived from tissue culture. They are genetically identical to parent plants. Applications: Mass propagation, disease-free plants.

29.                   Explain therapeutic proteins produced using biotechnology.
Answer: Proteins produced in microbes or transgenic animals for medical use:

• Insulin: Treat diabetes
• Clotting factors: Treat hemophilia
• Growth hormone: Treat growth disorders

30.                   Give two applications of gene therapy and stem cells in modern medicine.
Answer:

• Replacement of defective genes to treat inherited disorders
• Regeneration of damaged organs or tissues

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D. Microbial Biotechnology (Q31–40)

31.                   Explain fermentation and its industrial applications.
Answer: Fermentation is microbial conversion of organic substrates into valuable products. Applications:

• Alcohol production (Saccharomyces cerevisiae)
• Citric acid (Aspergillus niger)
• Antibiotics (penicillin)
• Enzymes (amylase, protease)

32.                   Describe single-cell protein (SCP) and its significance.
Answer: SCP is protein-rich microbial biomass. Significance: Supplements nutrition, alternative protein source, animal feed. Examples: Spirulina, yeast biomass.

33.                   Explain microbial bioremediation with example.
Answer: Use of microbes to degrade environmental pollutants. Example: Pseudomonas degrades oil spills. Significance: Reduces environmental pollution and restores ecosystems.

34.                   Explain microbial leaching with example.
Answer: Microbes extract metals from ores. Example: Thiobacillus ferrooxidans for copper extraction. Significance: Environmentally friendly metal extraction.

35.                   Describe probiotics and their applications.
Answer: Beneficial microbes enhancing gut health. Applications: Yogurt, digestive health, prevention of intestinal infections.

36.                   Explain production of industrial enzymes using microbes.
Answer: Microbes like Aspergillus and Bacillus produce enzymes like amylase, protease, and lipase, used in detergents, food, textile, and pharmaceutical industries.

37.                   Describe biogas production and its importance.
Answer: Anaerobic digestion of organic waste by microbes produces methane-rich biogas. Importance: Renewable energy, reduces dependence on fossil fuels, environmentally friendly.

38.                   Explain biofertilizers and their role in agriculture.
Answer: Microbes like Rhizobium, Azospirillum, and Azotobacter fix atmospheric nitrogen, enhancing soil fertility naturally. Significance: Reduces chemical fertilizer use, promotes sustainable agriculture.

39.                   Explain the role of lactic acid bacteria in food industry.
Answer: Lactobacillus and Streptococcus ferment milk to produce yogurt and cheese. Significance: Enhances nutrition, preserves food, and improves gut health.

40.                   Give two industrial applications of microbes with examples.
Answer:

• Biofuel production: Ethanol from yeast
• Antibiotics: Penicillin from Penicillium

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E. Plant Biotechnology (Q41–50)

41.                   Explain plant tissue culture and its applications.
Answer: In vitro growth of plant cells in nutrient media. Applications:

• Mass propagation of plants
• Production of disease-free plants
• Conservation of endangered species

42.                   Explain micropropagation in detail.
Answer: Technique for mass multiplication of plants using tissue culture. Steps:

• Explant selection
• Callus formation
• Shoot and root induction using auxins and cytokinins
• Hardening and transplantation

43.                   Explain somatic hybridization in plants.
Answer: Fusion of somatic cells from different plant species to produce hybrid plants with desired traits. Applications: Novel crop varieties, disease resistance.

44.                   Explain the role of auxins and cytokinins in tissue culture.
Answer:

• Auxins: Promote root formation
• Cytokinins: Promote shoot formation and cell division

45.                   Describe hardening of tissue-cultured plants.
Answer: Gradual acclimatization of plants to natural conditions to ensure survival post-transplantation.

46.                   Explain Golden Rice and its significance.
Answer: Rice genetically modified to produce beta-carotene. Significance: Addresses Vitamin A deficiency, improves nutrition in developing countries.

47.                   Explain the role of Agrobacterium tumefaciens in GM plant production.
Answer: Transfers T-DNA into plant cells, allowing integration of desired genes into plant genome to produce GM plants.

48.                   Give one example of a GM plant and explain its trait.
Answer: Bt cotton – contains Bacillus thuringiensis gene, producing insecticidal proteins to protect against bollworms.

49.                   Explain the difference between callus and somatic embryos.
Answer:

• Callus: Undifferentiated mass of cells
• Somatic embryo: Differentiated structure formed from callus that can develop into a whole plant

50.                   Describe the importance of plant biotechnology in agriculture and medicine.
Answer:

• Agriculture: Pest-resistant crops, higher yield, biofortified crops
• Medicine: Plants producing therapeutic proteins (pharming), production of vaccines and drugs