Q10. A bioreactor in industrial biotechnology is a vessel mainly designed to:
[RRB NTPC — Practice]
- (a) Record gravitational waves
- (b) Grow cells or conduct controlled biological reactions
- (c) Separate planetary gases
- (d) Store only dry minerals
Answer: (b) Grow cells or conduct controlled biological reactions
Explanation: Bioreactors support biological processes under controlled conditions such as temperature, pH, mixing and oxygen supply. They are used to produce enzymes, fermented products, pharmaceuticals and cell-derived materials. Different organisms require different reactor designs.
Q9. In India, the then Genetic Engineering Approval Committee functioned under which Union ministry?
[UPSC CSE (Pre) 2003]
- (a) Ministry of Environment and Forests
- (b) Ministry of Agriculture
- (c) Ministry of Commerce
- (d) Ministry of Rural Development
Answer: (a) Ministry of Environment and Forests
Explanation: The committee responsible for key approvals involving genetically engineered organisms was associated with the environment ministry. It is now commonly called the Genetic Engineering Appraisal Committee. The institutional name and current regulations should not be confused with wording used in the 2003 paper.
Q8. Which microorganism is widely used for commercial ethanol fermentation?
[RRB Group D — Practice]
- (a) Plasmodium vivax
- (b) Mycobacterium tuberculosis
- (c) Influenza virus
- (d) Saccharomyces cerevisiae
Answer: (d) Saccharomyces cerevisiae
Explanation: The yeast Saccharomyces cerevisiae converts sugars into ethanol and carbon dioxide during fermentation. Strain improvement and process optimisation increase productivity. Biotechnology includes traditional fermentation as well as modern genetic and cellular engineering.
Q7. Why are immobilised enzymes sometimes preferred in industrial bioprocessing?
[CGPSC — Practice]
- (a) They contain no amino acids
- (b) They work only at freezing temperatures
- (c) They may be reused and separated more easily from products
- (d) They never lose activity
Answer: (c) They may be reused and separated more easily from products
Explanation: Immobilising enzymes on or within a support can improve reusability, handling and product separation. Stability may also improve under suitable conditions. However, mass-transfer limitations and enzyme deactivation remain possible, so immobilisation is not always superior.
Q6. Which industrial application commonly uses microbial recombinant chymosin?
[UPSC CDS — Practice]
- (a) Petroleum drilling exclusively
- (b) Cheese making
- (c) Steel smelting
- (d) Glass colouring
Answer: (b) Cheese making
Explanation: Chymosin is a milk-clotting enzyme used in cheesemaking. Recombinant microorganisms can produce chymosin without relying entirely on extraction from calf stomachs. The product illustrates an industrial enzyme generated through molecular biotechnology.
Q5. When a single gene influences several distinct phenotypic traits, the phenomenon is called:
[UPSC CSE (Pre) 2002]
- (a) Pleiotropy
- (b) Apomixis
- (c) Polyploidy
- (d) Polyteny
Answer: (a) Pleiotropy
Explanation: Pleiotropy occurs when one gene contributes to multiple observable traits. A change in that gene may consequently influence several organs or physiological functions. Sickle-cell disease provides a familiar example, linking haemoglobin variation with diverse clinical consequences.
Q4. Phytoremediation is the use of which organisms to treat contaminated surroundings?
[UPSC NDA — Practice]
- (a) Viruses only
- (b) Fish alone
- (c) Protozoa only
- (d) Plants
Answer: (d) Plants
Explanation: Phytoremediation uses plants and associated root-zone processes to extract, stabilise or transform certain environmental pollutants. Its suitability varies with contaminant type, root depth and growth conditions. It is often slower than aggressive engineering-based cleanup methods.
Q3. A biosensor combines biological recognition with:
[State PSC — Practice]
- (a) An entire planted forest
- (b) Only a mechanical gear
- (c) A transducer that generates a measurable signal
- (d) A compulsory living human donor
Answer: (c) A transducer that generates a measurable signal
Explanation: A biosensor links a biological recognition element, such as an enzyme or antibody, with a device that converts the interaction into a signal. Biosensors are used in glucose monitoring, food testing and environmental analysis.
Q2. Which statement best captures an important biosafety principle for genetically engineered organisms?
[UPSC CSE — Practice]
- (a) Assume all engineered organisms are equally dangerous
- (b) Assess risks case by case before environmental or clinical use
- (c) Permit release without any evaluation
- (d) Ignore gene transfer and ecological effects
Answer: (b) Assess risks case by case before environmental or clinical use
Explanation: Biosafety assessments consider an organism, its introduced trait, intended use and receiving environment. Issues may include allergenicity, unintended effects, gene flow and ecological interactions. Evidence-based regulation aims to balance potential benefits against identifiable risks.
Q1. Which molecular method is especially useful in testing the biological paternity of a child?
[UP Lower Subordinate (Pre) 2002]
- (a) DNA fingerprinting
- (b) Artificial cloning
- (c) Recombinant hormone synthesis
- (d) Gene therapy
Answer: (a) DNA fingerprinting
Explanation: A child inherits genetic variants from both biological parents. DNA profiling examines multiple variable loci to assess whether the alleged parent contributed the expected alleles. The interpretation relies on population statistics and reliable laboratory procedures.
