Competency-Based Question Bank: Biotechnology and its Applications

Section A: Competency-Based Multiple Choice Questions (Application & Analysis)

1. Analyze the Immune Response: A person is suspected to have an HIV infection. Which of the following diagnostic tests relies on the principle of antigen-antibody interaction to detect the presence of the virus (or antibodies against it)? a) Serum Analysis b) ELISA c) Urine Analysis d) Widal Test Answer: b) ELISA Explanation: ELISA (Enzyme-Linked Immunosorbent Assay) uses the specific binding between an antigen and its antibody. In HIV testing, it detects the presence of antibodies produced by the body against the HIV virus.

2. Evaluate the Technology: Why is RNA interference (RNAi) considered a novel strategy for pest control in agriculture? a) It kills the pest by producing a toxic protein. b) It silences a specific mRNA of the pest, preventing the translation of a crucial protein. c) It strengthens the plant's cell wall. d) It produces antibodies against the pest. Answer: b) It silences a specific mRNA of the pest... Explanation: RNAi uses double-stranded RNA to trigger the degradation of a specific homologous mRNA sequence in the pest, effectively "silencing" a vital gene and killing the pest.

3. Predict the Outcome: If a diabetic patient is treated with insulin extracted from a slaughtered pig, what is a potential immune complication compared to using genetically engineered human insulin (Humulin)? a) The pig insulin will be too potent, causing hypoglycemia. b) The patient may develop antibodies against the foreign protein, reducing efficacy or causing allergies. c) The pig insulin will not bind to human receptors. d) There is no difference; insulin is identical across species. Answer: b) The patient may develop antibodies against the foreign protein... Explanation: Animal insulin has a slightly different amino acid sequence than human insulin. The human immune system may recognize it as "foreign" and mount an immune response (allergy or resistance).

4. Assertion (A): The first clinical gene therapy was given to a 4-year-old girl with Adenosine Deaminase (ADA) deficiency. Reason (R): This therapy provided a permanent cure for the disease. a) Both A and R are true and R is the correct explanation of A. b) Both A and R are true but R is not the correct explanation of A. c) A is true but R is false. d) A is false but R is true. Answer: c) A is true but R is false. Explanation: The therapy involved infusing genetically engineered lymphocytes. Since lymphocytes are not immortal and die over time, the patient required periodic infusions. It was not a permanent cure (which requires stem cell therapy).

5. Biopiracy Case: A foreign company patents a product made from the Neem tree for its antifungal properties. Why might the Indian government challenge this patent? a) Because Neem trees only grow in India. b) Because the company did not pay the Indian government. c) Because the antifungal properties of Neem are "Traditional Knowledge" and thus not a novel invention (Prior Art). d) Because the product is ineffective. Answer: c) Because the antifungal properties of Neem are "Traditional Knowledge"... Explanation: For a patent to be valid, the invention must be novel. Since the uses of Neem are recorded in ancient Indian texts (Traditional Knowledge), they constitute "Prior Art," making the patent invalid.

6. Mechanism of Action: How does the Cry protein (Bt toxin) specifically kill lepidopteran larvae (caterpillars) without harming the plant or humans? a) It is activated only by the acidic pH of the human stomach. b) It is activated by the alkaline pH of the insect gut, creating pores in the midgut epithelial cells. c) It attacks the insect's nervous system directly. d) It starves the insect by blocking its mouth. Answer: b) It is activated by the alkaline pH of the insect gut... Explanation: The protein exists as an inactive protoxin. The specific alkaline conditions in the caterpillar's gut solubilize and activate the toxin, which then binds to the gut wall and causes lysis.

7. Ethical Reasoning: What is the primary ethical concern regarding the creation of "transgenic animals" like mice for cancer research? a) They are expensive to produce. b) They may escape into the wild and breed. c) They are subjected to intentional suffering and disease for human benefit. d) They taste different from normal mice. Answer: c) They are subjected to intentional suffering... Explanation: Transgenic models (Oncomice) are designed to develop tumors. The ethical dilemma is whether it is right to cause pain to animals to alleviate human suffering.

8. Identify the Product: "Rosie," the first transgenic cow, produced milk that was nutritionally superior for human babies. What was the specific enrichment? a) Human Insulin b) Alpha-1-antitrypsin c) Human alpha-lactalbumin d) Vitamin A Answer: c) Human alpha-lactalbumin Explanation: This protein made the cow's milk more balanced and similar to human breast milk, making it easier for babies to digest.

9. Diagnostic Logic: Why is PCR preferred over traditional urine/serum analysis for detecting early-stage cancer or viral infections? a) PCR is cheaper. b) PCR can detect the pathogen/gene even at very low concentrations by amplification. c) PCR does not require a blood sample. d) PCR is faster. Answer: b) PCR can detect the pathogen/gene even at very low concentrations... Explanation: Traditional tests rely on detecting antibodies or high loads of pathogen. In early stages, these are low. PCR amplifies the genetic material millions of times, making even a single molecule detectable.

10. Gene Therapy Strategy: To permanently cure ADA deficiency using gene therapy, at what stage should the functional ADA gene be introduced? a) Into the lymphocytes of an adult patient. b) Into the bone marrow of a child. c) Into cells at the early embryonic stages. d) Via a vaccine. Answer: c) Into cells at the early embryonic stages. Explanation: If the gene is integrated into the genome of embryonic cells, it will be passed on to all subsequent daughter cells (including stem cells) as the organism develops, resulting in a lifelong cure.

11. Cry Gene Specificity: Which specific Cry gene would you use to control the "Corn Borer"? a) cryIAb b) cryIAc c) cryIIAb d) cryIIIAb Answer: a) cryIAb Explanation: Different Cry genes target different pests. cryIAb is specific to the Corn Borer, while cryIAc and cryIIAb target Cotton Bollworms.

12. Golden Rice Logic: Golden Rice is a biofortified crop designed to solve which specific health problem in developing nations? a) Scurvy (Vitamin C deficiency) b) Night Blindness (Vitamin A deficiency) c) Rickets (Vitamin D deficiency) d) Anemia (Iron deficiency) Answer: b) Night Blindness (Vitamin A deficiency) Explanation: Golden Rice contains genes for Beta-carotene, which the human body converts into Vitamin A. Vitamin A deficiency is a leading cause of childhood blindness.

13. Structure of Insulin: In the maturation of pro-insulin to insulin, which part is removed? a) A-peptide b) B-peptide c) C-peptide d) Disulfide bridges Answer: c) C-peptide Explanation: Pro-insulin contains A, B, and C chains. The C-peptide connects A and B. During maturation, the C-peptide is cleaved off, leaving A and B linked by disulfide bridges.

14. Nematode Resistance: In the RNAi strategy to protect tobacco plants from Meloidegyne incognita, the nematode-specific genes were introduced using which vector? a) Bacillus thuringiensis b) Agrobacterium tumefaciens c) Retrovirus d) pBR322 Answer: b) Agrobacterium tumefaciens Explanation: Agrobacterium is the natural genetic engineer of plants and is commonly used to transfer foreign DNA (in this case, the nematode gene) into plant cells.

15. Concept Application: Which of the following is NOT a direct application of transgenic animals? a) Testing vaccine safety (e.g., Polio). b) Producing biological products (e.g., alpha-1-antitrypsin). c) Studying gene regulation. d) Cloning humans. Answer: d) Cloning humans. Explanation: Cloning humans is an ethical and legal taboo and is not a standard application of transgenic animal technology.

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Section B: Case-Study & Source-Based Questions

Case Study 1: The Cotton Crisis

A farmer in Maharashtra grows conventional cotton. Every year, he loses 30% of his crop to bollworms despite spraying expensive chemical pesticides. His neighbor switches to Bt Cotton and reports higher yields with almost zero pesticide use.

16. Analyze: Why did the neighbor's crop survive the bollworms? a) The cotton bolls were harder to eat. b) The plants produced an intracellular crystalline toxin that killed the larvae upon ingestion. c) The plants released a gas that repelled the moths. d) The plants attracted birds that ate the worms. Answer: b) The plants produced an intracellular crystalline toxin... Explanation: Bt cotton contains the Cry gene which produces a toxic protein crystal. When the worm eats the leaf/boll, the toxin kills it.

17. Evaluate: What is a potential environmental risk of growing Bt Cotton that the farmer should be aware of? a) It uses more water. b) It might kill beneficial insects like bees (pollinators) if the toxin is not specific enough (though modern Bt is highly specific). c) It will make the soil toxic. d) The bollworms might eventually develop resistance to the toxin. Answer: d) The bollworms might eventually develop resistance to the toxin. Explanation: Continuous exposure to the same toxin creates a strong selection pressure. Resistant worms survive and breed, potentially rendering the Bt crop ineffective over time.

18. Economic Impact: How does Bt cotton primarily benefit the farmer economically? a) By selling the seeds at a higher price. b) By reducing the cost of purchasing chemical pesticides. c) By growing faster. d) By requiring less fertilizer. Answer: b) By reducing the cost of purchasing chemical pesticides. Explanation: While Bt seeds are more expensive, the massive savings on pesticide sprays and labor, plus the higher yield (prevented loss), result in a net profit.

Case Study 2: The SCID Patient

Ashanti, a 4-year-old girl, suffers from Severe Combined Immunodeficiency (SCID) due to a lack of the enzyme Adenosine Deaminase (ADA). Without this enzyme, her T-lymphocytes die, leaving her defenseless against infections.

19. Mechanism: Why does ADA deficiency destroy the immune system? a) ADA is needed for hemoglobin synthesis. b) ADA is crucial for the breakdown of toxic metabolites that accumulate and kill T-cells. c) ADA is a structural component of antibodies. d) ADA activates the thymus. Answer: b) ADA is crucial for the breakdown of toxic metabolites... Explanation: ADA converts adenosine (toxic) to inosine (non-toxic). Without ADA, toxic adenosine builds up inside T-cells and kills them.

20. Treatment Evaluation: Doctors perform gene therapy by extracting her lymphocytes, inserting a good ADA gene, and re-infusing them. Why is this not a permanent cure? a) The virus eats the gene. b) Lymphocytes are not immortal; they die and are replaced by new (defective) ones from the bone marrow. c) The gene mutates back. d) The body rejects the cells. Answer: b) Lymphocytes are not immortal... Explanation: The treated cells eventually die naturally. Since the patient's bone marrow stem cells (the source) still have the defect, they continue to produce defective lymphocytes, requiring repeat therapy.

Case Study 3: The Golden Grain

Scientists engineered "Golden Rice" to contain genes for Beta-carotene biosynthesis from the daffodil plant.

21. Nutritional Pathway: Once consumed, what happens to the Beta-carotene in the human body? a) It is excreted. b) It is converted into Vitamin A in the liver. c) It turns the skin gold. d) It acts as an antibiotic. Answer: b) It is converted into Vitamin A in the liver. Explanation: Beta-carotene is "Pro-Vitamin A". Our body enzymes cleave it to produce Retinol (Vitamin A).

22. Debate: Critics argue that Golden Rice is not the best solution. What is a valid nutritional counter-argument? a) It is poisonous. b) It is better to encourage a diversified diet (vegetables/fruits) rather than relying on a single staple crop. c) Rice cannot hold vitamins. d) It tastes bad. Answer: b) It is better to encourage a diversified diet... Explanation: Relying on one biofortified crop might not address other deficiencies (iron, zinc). A diverse diet naturally provides all nutrients and is more sustainable.

23. Regulation: Before Golden Rice can be sold to farmers, which body in India must approve its environmental safety? a) ICMR b) GEAC (Genetic Engineering Appraisal Committee) c) WHO d) FCI Answer: b) GEAC (Genetic Engineering Appraisal Committee) Explanation: The GEAC is the apex body in India responsible for approving the environmental release of any Genetically Modified Organism (GMO).

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Section C: Creating, Designing & Critical Thinking

24. Designing a Gene Therapy Protocol: You are a scientist aiming to treat Cystic Fibrosis (caused by a defective CFTR gene in lung cells) using gene therapy.

• Vector Choice: Which vector would you choose to deliver the gene to the lungs? (Retrovirus, Adenovirus, or Liposome spray?). Explain why.
• Strategy: Would you target stem cells or somatic cells? Why? Answer:
• Vector: I would choose Adenovirus (modified to be safe) or a Liposome spray. Retroviruses integrate into the genome and pose a cancer risk. Adenoviruses naturally infect lungs and are good for delivering genes to respiratory tissue. Liposomes are non-viral and safer.
• Strategy: I would target Somatic Cells (lining of the lungs). Targeting stem cells (Germline) is ethically restricted/illegal in humans. Treating the lung lining directly relieves symptoms.

25. Ethical Evaluation (Biopiracy): Scenario: An American company takes a sample of a unique fungus from the soil of the Kerala rainforests. They isolate a new antibiotic from it and patent the drug globally without informing the Indian authorities.

• Analysis: Is this biopiracy? Why or why not?
• Action: What steps should the Indian government take under the Convention on Biological Diversity (CBD)? Answer:
• Analysis: Yes, this is Biopiracy. It involves the unauthorized use of biological resources from a developing country without "Prior Informed Consent" and without "Access and Benefit Sharing".
• Action: India should challenge the patent internationally. Under the CBD and Nagoya Protocol, the company is obligated to share a portion of the profits/benefits with India as the country of origin.

26. Creating a Diagram: Draw a schematic of the Maturation of Insulin.

• Show: Pro-insulin (with A, B, and C chains) -> Enzymatic cleavage -> Mature Insulin (A and B chains linked by disulfide bridges) + Free C-peptide. Answer: (Visual Description)

1. Stage 1 (Pro-insulin): Draw a single long polypeptide chain folded on itself. Label three regions: Chain A, Chain B, and a connecting loop Chain C. Show disulfide bonds connecting A and B.
2. Arrow: Label "Enzymatic Processing".
3. Stage 2 (Mature Insulin + C-peptide): Draw Chain A and Chain B connected by two disulfide bonds (active Insulin). Separate from them, draw the removed loop (C-peptide).

27. Formulating a Hypothesis: Observation: Some pests have started surviving on Bt Cotton fields (Resistance).

• Hypothesis: How did this resistance evolve? (Darwinian selection).
• Solution: Propose a strategy to delay this resistance (e.g., Refugia strategy - planting non-Bt cotton rows). Answer:
• Hypothesis: In the initial pest population, a few rare individuals had a random mutation that modified their gut receptors, making them immune to the Bt toxin. When the field was sprayed with Bt, everyone died except these mutants. They bred and passed the resistance gene to the next generation, eventually creating a resistant population.
• Solution: Refugia Strategy. Plant rows of non-Bt cotton around the Bt field. This allows non-resistant pests to survive and breed with the resistant ones, diluting the resistance genes in the population and preventing them from becoming fixed.

28. Scenario Analysis (Diagnosis): A patient has a suspected HIV infection, but it is very early (window period). The ELISA test comes back negative (no antibodies yet).

• Alternative: What molecular diagnostic test can detect the virus itself (genetic material) at this stage?
• Principle: Briefly explain how this technique amplifies the signal. Answer:
• Test: PCR (Polymerase Chain Reaction).
• Principle: PCR uses primers specific to the HIV genetic sequence. Even if only a few viral DNA/RNA molecules are present, the enzyme Taq polymerase synthesizes millions of copies of that sequence in a few hours. This massive amplification makes the virus detectable long before the body produces enough antibodies for ELISA.

29. Critical Thinking: "Transgenic animals are 'biological factories'."

• Justify: Explain this statement using the example of Alpha-1-antitrypsin production. Why is it cheaper/better to produce this protein in sheep milk than in a chemical lab? Answer:
• Justification: Transgenic animals (like sheep) act as living bioreactors. By inserting the gene for Alpha-1-antitrypsin (used for Emphysema) into the sheep's genome with a mammary-specific promoter, the sheep secretes the protein directly into its milk.
• Advantage: Synthesizing complex human proteins chemically is incredibly difficult and expensive. Animals possess the natural cellular machinery to fold and modify the protein correctly. Harvesting it from milk is non-invasive and provides a renewable, high-volume supply.

30. Debating GMOs: Topic: "GMO labeling should be mandatory."

• Task: Provide one argument from a Consumer Rights perspective (Pro-labeling) and one argument from an Industry/Scientific perspective (Anti-labeling/Neutral). Answer:
• Consumer Rights: Consumers have the "Right to Know" what is in their food. Mandatory labeling allows people with ethical, religious, or health concerns (allergies) to make informed choices.
• Industry/Scientific: Labeling implies that GMOs are somehow different or "unsafe," which stigmatizes the product despite scientific consensus on their safety (Substantial Equivalence). It increases costs for segregation and packaging without adding nutritional information.

31. Developing a Solution: You want to protect a tomato crop from a nematode that eats the roots. You decide to use RNA interference (RNAi).

• Design: What gene will you insert into the tomato plant? (A gene from the tomato or the nematode?).
• Mechanism: How will the plant kill the worm? (dsRNA -> Silencing essential worm gene). Answer:
• Design: I will insert a gene from the nematode itself (a vital housekeeping gene necessary for its survival) into the tomato plant.
• Mechanism: The tomato plant will transcribe this gene to produce Double-Stranded RNA (dsRNA). When the nematode eats the tomato roots, it ingests this dsRNA. Inside the worm, the RNAi machinery recognizes the dsRNA, chops it up, and uses the pieces to destroy the worm's own mRNA for that vital gene. The gene is silenced, and the worm dies.