Class 12/Question Bank/Competency Based
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Competency Based Questions on Application of Biotechnology
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.
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.
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.
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).
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.
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.
26. Creating a Diagram: Draw a schematic of the Maturation of Insulin.
27. Formulating a Hypothesis: Observation: Some pests have started surviving on Bt Cotton fields (Resistance).
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).
29. Critical Thinking: "Transgenic animals are 'biological factories'."
30. Debating GMOs: Topic: "GMO labeling should be mandatory."
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).
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