Chapter 10: Biotechnology and its Applications Application Questions | biology Class 12 CBSE

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Chapter 10: Biotechnology and its Applications Application Questions | biology Class 12 CBSE | ByteNotes.in

Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 1

Applied Concept

A farmer in Maharashtra notices that her Bt cotton crop has fewer bollworm attacks than her neighbour's non-Bt cotton, even though no pesticide was applied. With reference to the chapter, explain the biological mechanism responsible for this observation.

Bt cotton plants carry the cryIAc or cryIIAb gene from Bacillus thuringiensis, which encodes an insecticidal Cry protein (protoxin) expressed throughout the plant tissue including the cotton bolls and leaves that bollworms feed on.
When a bollworm ingests plant material, the alkaline pH of its midgut converts the inactive protoxin into active Bt toxin, which binds to midgut epithelial cells and creates pores causing cell swelling, lysis, and insect death.
Because the toxin is produced constitutively inside the plant cells, the bollworms are exposed to it whenever they feed, providing continuous protection without any externally applied pesticide — explaining the farmer's observation of reduced bollworm attacks.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 2

Applied Concept

A biotechnology student is trying to obtain virus-free sugarcane plants for a replanting project. With reference to the principle of tissue culture described in the chapter, suggest the most appropriate strategy and justify your choice.

The student should use meristem culture — specifically culturing the apical or axillary meristematic tissue from infected sugarcane plants — because even in virus-infected plants, the meristem remains free of the virus.
The excised meristem is grown in vitro under sterile conditions in a nutrient medium containing a carbon source (sucrose), inorganic salts, vitamins, amino acids, and growth regulators (auxins and cytokinins) to regenerate whole plants.
The resulting plantlets will be genetically identical to the parent (somaclones) and virus-free, making them ideal for replanting projects that require healthy, uniform planting material; this approach has already been validated for sugarcane by scientists.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 3

Applied Concept

A doctor suspects that a patient may be in the early stages of HIV infection, but conventional serum analysis shows no abnormality. Which molecular diagnostic technique would you recommend and why?

PCR (Polymerase Chain Reaction) should be recommended, as it can detect very low concentrations of HIV nucleic acid in the patient's blood long before disease symptoms appear and before conventional serum analysis can identify the infection.
PCR amplifies specific HIV RNA or DNA sequences exponentially, making even trace amounts detectable; this is critical in early-stage HIV infection when viral load is low and the immune response has not yet generated detectable levels of antibodies.
The chapter states that PCR is routinely used to detect HIV in suspected AIDS patients and is a powerful tool for identifying infections at a stage when the pathogen concentration is too low for conventional diagnostic methods to detect.

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Application Question

Hard difficulty • Concept in a practical situation

Hard

Question 4

Applied Concept

An agricultural scientist wants to protect potato crops from nematode infestation without using chemical nematicides. Based on the RNAi strategy described in the chapter, outline the steps she would follow.

The scientist would identify genes essential for the survival of the target nematode species in the host plant, then construct a DNA sequence that would produce both sense RNA and anti-sense RNA corresponding to those nematode genes when expressed in the potato plant.
This construct would be introduced into the potato plant using Agrobacterium tumefaciens as a vector; inside the plant cells, the sense and anti-sense RNA strands would anneal to form double-stranded RNA (dsRNA).
The dsRNA would initiate RNAi, silencing the nematode's essential mRNA and preventing the nematode from producing the proteins it needs to survive within the host plant, thus protecting the potato crop without any external chemical treatment.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 5

Applied Concept

A pharmaceutical company in the 1970s was producing insulin from slaughtered pigs for diabetic patients. Describe two problems faced by patients using this insulin, and explain how recombinant DNA technology solved these problems.

Animal-derived insulin caused allergic reactions and other types of immunological responses in some patients because it was not identical to the human insulin molecule — minor structural differences were recognised as foreign by the human immune system.
Additionally, insulin from animal sources carried risks of contamination and infection, and its supply was entirely dependent on the availability of slaughtered animals, making large-scale, reliable production difficult.
Recombinant DNA technology solved both problems: Eli Lilly produced human insulin in E. coli by introducing the genes for chains A and B separately, then combining them with disulfide bonds to produce insulin structurally identical to human insulin — eliminating immune reactions and infection risks, with scalable bacterial production.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 6

Applied Concept

With reference to the chapter, explain why a child born with ADA deficiency has a severely compromised immune system, and describe how gene therapy can address this condition.

Adenosine deaminase (ADA) is a crucial enzyme for the proper functioning of the immune system; its deficiency — caused by deletion of the ADA gene — prevents lymphocytes from functioning normally, leaving the child vulnerable to infections.
In gene therapy, lymphocytes are isolated from the patient's blood, cultured outside the body, and a functional ADA cDNA is introduced into them via a retroviral vector, enabling these cells to produce the missing enzyme.
The genetically corrected lymphocytes are then re-infused into the patient, restoring immune function; however, since lymphocytes are mortal, the procedure must be repeated periodically — a permanent solution would require ADA gene delivery into early embryonic marrow cells.

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Application Question

Hard difficulty • Concept in a practical situation

Hard

Question 7

Applied Concept

An Indian biotech firm is studying a drought-resistant gene found in a desert plant. An international company learns of this and files a patent for this gene's application in crop improvement. With reference to the chapter, what ethical issue does this represent, and what legal mechanisms exist in India to address it?

This scenario represents biopiracy — the use of biological resources and associated traditional or scientific knowledge without proper authorisation from the source country and without compensatory payment, exploiting India's biodiversity for commercial gain.
India's GEAC (Genetic Engineering Approval Committee) regulates GM research domestically, but for intellectual property protection, the second amendment of the Indian Patents Bill provides legal tools to counter such unauthorised exploitation of India's bio-resources.
The amendment includes emergency provisions, research and development protections, and patent term provisions that aim to prevent foreign entities from claiming rights over biological material and innovations derived from India's rich biological heritage — similar to the legal battles fought over Basmati rice and neem patents.

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Application Question

Hard difficulty • Concept in a practical situation

Hard

Question 8

Applied Concept

A researcher wants to produce a transgenic goat that secretes a human blood-clotting factor in its milk for treating haemophilia. Based on the principles described in the chapter, what approach would she use and what precedent exists for this strategy?

The researcher would identify the DNA sequence (gene) coding for the human blood-clotting factor, then introduce this gene into the goat's genome using recombinant DNA technology so that the gene is expressed specifically in the mammary gland and the protein is secreted in milk.
This approach is supported by the chapter's precedent of the transgenic cow Rosie (1997), which was created by introducing the human alpha-lactalbumin gene and produced milk enriched with this human protein at 2.4 g/L — demonstrating the feasibility of producing human proteins via transgenic animal milk.
Similarly, attempts to produce human alpha-1-antitrypsin (for treating emphysema) in transgenic animals confirm this as an established strategy for generating biological products in a cost-effective and scalable manner.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 9

Applied Concept

A food scientist claims that golden rice is a superior solution to Vitamin A deficiency in developing countries compared to dietary supplementation programs. Based on the chapter, explain what golden rice is and evaluate this claim.

Golden rice is a genetically modified variety of rice engineered to produce beta-carotene (a precursor to Vitamin A) in its edible grain — the name 'golden' refers to the yellow colour imparted by beta-carotene pigments.
It addresses Vitamin A deficiency by delivering the nutrient directly through a staple food crop that billions of people in Asia already consume, without requiring changes to dietary habits or distribution of supplements.
The chapter highlights enhanced nutritional value as a key benefit of GM crops; however, the broader debate — not covered in the chapter — includes considerations of dosage adequacy and access, but from the biotechnological standpoint, golden rice demonstrates how genetic modification can enhance a crop's nutritional profile to address public health challenges.

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Application Question

Medium difficulty • Concept in a practical situation

Medium

Question 10

Applied Concept

A scientist observes that a laboratory mouse does not develop Alzheimer's symptoms despite being genetically predisposed. She suspects that a new drug is responsible. Which type of experimental animal model described in the chapter would be most appropriate for testing this drug, and why?

Transgenic mice engineered to develop Alzheimer's disease — by introducing human genes associated with Alzheimer's pathology — would be the most appropriate model, as they mimic the disease progression seen in humans.
The chapter explicitly mentions that transgenic animal models exist for Alzheimer's disease, enabling investigation of new treatments; these models allow controlled study of the drug's effect on disease progression in a biological system similar to human Alzheimer's.
Using transgenic Alzheimer's mice ensures that the drug is tested in animals that genuinely develop the disease, providing more meaningful data than testing on non-Alzheimer's animals and reducing the number of experiments needed to reach statistically valid conclusions.

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Chapter sections

Chapter 10: Biotechnology and its Applications | Application Questions

A farmer in Maharashtra notices that her Bt cotton crop has fewer bollworm attacks than her neighbour's non-Bt cotton, even though no pesticide was applied. With reference to the chapter, explain the biological mechanism responsible for this observation.

A biotechnology student is trying to obtain virus-free sugarcane plants for a replanting project. With reference to the principle of tissue culture described in the chapter, suggest the most appropriate strategy and justify your choice.

A doctor suspects that a patient may be in the early stages of HIV infection, but conventional serum analysis shows no abnormality. Which molecular diagnostic technique would you recommend and why?

An agricultural scientist wants to protect potato crops from nematode infestation without using chemical nematicides. Based on the RNAi strategy described in the chapter, outline the steps she would follow.

A pharmaceutical company in the 1970s was producing insulin from slaughtered pigs for diabetic patients. Describe two problems faced by patients using this insulin, and explain how recombinant DNA technology solved these problems.

With reference to the chapter, explain why a child born with ADA deficiency has a severely compromised immune system, and describe how gene therapy can address this condition.

A researcher wants to produce a transgenic goat that secretes a human blood-clotting factor in its milk for treating haemophilia. Based on the principles described in the chapter, what approach would she use and what precedent exists for this strategy?

A food scientist claims that golden rice is a superior solution to Vitamin A deficiency in developing countries compared to dietary supplementation programs. Based on the chapter, explain what golden rice is and evaluate this claim.

A scientist observes that a laboratory mouse does not develop Alzheimer's symptoms despite being genetically predisposed. She suspects that a new drug is responsible. Which type of experimental animal model described in the chapter would be most appropriate for testing this drug, and why?

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