NCERT NEET Biology English Medium Part-1 | Chapter 28 : Biotechnology: Principles and processes.

NCERT NEET Biology English Medium Part-1 | Chapter 28 : Biotechnology: Principles and processes.

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Question 1. What does the European Federation of Biotechnology (EFB) definition of biotechnology specifically integrate?

1. a) Natural science and organisms, cells, parts thereof, and molecular analogues for products and services.
2. b) Genetic engineering and bioprocess engineering for product generation.
3. c) Traditional hybridization procedures with modern gene cloning.
4. d) In vitro fertilization and gene synthesis.

Answer: a.

Question 2. Which of the following best describes the primary limitation of traditional hybridization procedures used in plant and animal breeding?

1. a) They do not permit any variation in the genetic setup.
2. b) They often lead to the inclusion and multiplication of undesirable genes along with the desired ones.
3. c) They require strict maintenance of sterile environments.
4. d) They prevent the target organism from multiplying.

Answer: b.

Question 3. What is the specific DNA sequence responsible for initiating replication in a chromosome?

1. a) Promoter sequence.
2. b) Origin of replication.
3. c) Terminator region.
4. d) Palindromic nucleotide sequence.

Answer: b.

Question 4. Stanley Cohen and Herbert Boyer constructed the first artificial recombinant DNA molecule in which year?

1963. a) 1963.
1964. b) 1972.
1965. c) 1983.
1966. d) 1990.

Answer: b.

Question 5. The native plasmid used by Cohen and Boyer to link the antibiotic resistance gene was isolated from which organism?

1. a) Escherichia coli.
2. b) Agrobacterium tumefaciens.
3. c) Salmonella typhimurium.
4. d) Thermus aquaticus.

Answer: c.

Question 6. What role does DNA ligase play in the formation of recombinant DNA?

1. a) It cuts DNA at specific palindromic sequences.
2. b) It acts on cut DNA molecules and joins their ends.
3. c) It adds methyl groups to the DNA to restrict viral growth.
4. d) It synthesizes complementary DNA strands.

Answer: b.

Question 7. In 1963, two enzymes responsible for restricting the growth of bacteriophage in E. coli were isolated. What was the function of the enzyme that was NOT the restriction endonuclease?

1. a) It cut the DNA into fragments.
2. b) It added methyl groups to the DNA.
3. c) It removed nucleotides from the ends of the DNA.
4. d) It joined the broken fragments of DNA.

Answer: b.

Question 8. Which was the first restriction endonuclease to be isolated and characterized?

1. a) EcoRI.
2. b) BamHI.
3. c) HindII.
4. d) pBR322.

Answer: c.

Question 9. HindII always cuts DNA molecules at a particular point by recognizing a specific sequence consisting of how many base pairs?

1. a) Four base pairs.
2. b) Six base pairs.
3. c) Eight base pairs.
4. d) Ten base pairs.

Answer: b.

Question 10. In the nomenclature of restriction enzymes, such as EcoRI, what does the Roman numeral 'I' indicate?

1. a) The strain of the bacteria.
2. b) The order in which the enzyme was isolated from that bacterial strain.
3. c) The genus of the prokaryotic cell.
4. d) The specific sequence it recognizes.

Answer: b.

Question 11. Which class of nucleases removes nucleotides from the ends of the DNA molecule?

1. a) Endonucleases.
2. b) Exonucleases.
3. c) Ligases.
4. d) Polymerases.

Answer: b.

Question 12. Restriction endonucleases inspect the length of a DNA sequence to find their specific recognition sequence. What specific structure do they cut?

1. a) The hydrogen bonds between the nitrogenous bases.
2. b) The sugar-phosphate backbones of the two DNA strands.
3. c) The phosphodiester bonds at the ends of the DNA only.
4. d) The disulfide bonds in the DNA double helix.

Answer: b.

Question 13. EcoRI cuts DNA between which two bases in its palindromic recognition sequence GAATTC?

1. a) Between G and A.
2. b) Between A and A.
3. c) Between A and T.
4. d) Between T and C.

Answer: a.

Question 14. What is the primary function of the "sticky ends" left by restriction endonucleases?

1. a) They act as a marker for gel electrophoresis.
2. b) They facilitate the action of the enzyme DNA ligase by forming hydrogen bonds with complementary counterparts.
3. c) They initiate the replication of DNA in the host cell.
4. d) They prevent the vector from self-ligating.

Answer: b.

Question 15. In gel electrophoresis, DNA fragments move towards which electrode?

1. a) Cathode, because DNA is positively charged.
2. b) Cathode, because DNA is negatively charged.
3. c) Anode, because DNA is positively charged.
4. d) Anode, because DNA is negatively charged.

Answer: d.

Question 16. What is the most commonly used matrix in gel electrophoresis for separating DNA fragments?

1. a) Polyacrylamide.
2. b) Agarose.
3. c) Silica gel.
4. d) Ethidium bromide.

Answer: b.

Question 17. In agarose gel electrophoresis, the separation of DNA fragments is based on their size. Which fragments move the farthest?

1. a) The largest fragments.
2. b) The smallest fragments.
3. c) Fragments with the highest GC content.
4. d) Fragments with the most sticky ends.

Answer: b.

Question 18. How are separated DNA fragments visualized after gel electrophoresis?

1. a) By staining with methylene blue and viewing under visible light.
2. b) By staining with ethidium bromide and exposing to UV radiation.
3. c) By staining with iodine and viewing under an electron microscope.
4. d) By using a spectrophotometer without staining.

Answer: b.

Question 19. The process of extracting separated bands of DNA from the agarose gel piece is known as what?

1. a) Spooling.
2. b) Elution.
3. c) Annealing.
4. d) Downstream processing.

Answer: b.

Question 20. Why are bacteriophages often considered highly advantageous as cloning vectors?

1. a) They cannot replicate without integrating into the host chromosome.
2. b) They possess an inherent antibiotic resistance gene.
3. c) Because of their high number per cell, they have very high copy numbers of their genome within bacterial cells.
4. d) They lack an origin of replication.

Answer: c.

Question 21. Which feature of a cloning vector controls the copy number of the linked DNA?

1. a) Selectable marker.
2. b) Recognition site.
3. c) Origin of replication (ori).
4. d) Promoter sequence.

Answer: c.

Question 22. What is the primary purpose of a selectable marker in a cloning vector?

1. a) To initiate the replication process.
2. b) To identify and eliminate non-transformants and selectively permit the growth of transformants.
3. c) To provide a site for restriction enzymes to cut.
4. d) To increase the expression of the target protein.

Answer: b.

Question 23. Which of the following is commonly used as a selectable marker for E. coli?

1. a) Genes encoding resistance to ampicillin.
2. b) Genes encoding for the enzyme Taq polymerase.
3. c) Genes for beta-galactosidase expression in humans.
4. d) Genes responsible for nitrogen fixation.

Answer: a.

Question 24. For a cloning vector to be effective, how many recognition sites for a specific restriction enzyme should it ideally have?

1. a) Multiple sites to ensure complete digestion.
2. b) Only one, preferably, to prevent the vector from breaking into several pieces.
3. c) At least three sites spread across the vector.
4. d) None, as recognition sites interfere with replication.

Answer: b.

Question 25. In the pBR322 cloning vector, where is the restriction site for BamHI located?

1. a) Within the origin of replication (ori).
2. b) Within the ampicillin resistance gene.
3. c) Within the tetracycline resistance gene.
4. d) Within the rop gene.

Answer: c.

Question 26. What happens if a foreign DNA is ligated at the BamHI site of the tetracycline resistance gene in pBR322?

1. a) The recombinant plasmid loses its ampicillin resistance.
2. b) The recombinant plasmid loses its tetracycline resistance due to insertional inactivation.
3. c) The origin of replication is destroyed.
4. d) The host cell dies immediately upon transformation.

Answer: b.

Question 27. When using insertional inactivation of the beta-galactosidase gene for screening, what color do recombinant colonies produce on a chromogenic substrate?

1. a) Blue.
2. b) Red.
3. c) White/Colorless.
4. d) Green.

Answer: c.

Question 28. Which of the following bacteria acts as a natural genetic engineer in plants by transferring 'T-DNA'?

1. a) Escherichia coli.
2. b) Bacillus thuringiensis.
3. c) Agrobacterium tumefaciens.
4. d) Thermus aquaticus.

Answer: c.

Question 29. Retroviruses in animals have the ability to transform normal cells into which type of cells?

1. a) Bacterial cells.
2. b) Fungal cells.
3. c) Cancerous cells.
4. d) Stem cells.

Answer: c.

Question 30. Why is DNA considered a hydrophilic molecule?

1. a) Because of its nitrogenous bases.
2. b) Because it contains a sugar-phosphate backbone with negatively charged phosphate groups.
3. c) Because it is double-stranded.
4. d) Because it lacks oxygen atoms in its sugar moiety.

Answer: b.

Question 31. To make bacterial cells "competent" to take up plasmid DNA, they are treated with a specific concentration of a divalent cation. Which ion is commonly used?

1. a) Sodium.
2. b) Calcium.
3. c) Potassium.
4. d) Magnesium.

Answer: b.

Question 32. In the "heat shock" method for transforming bacteria, the cells are briefly incubated at what temperature?

1. a) 25 degrees Celsius.
2. b) 37 degrees Celsius.
3. c) 42 degrees Celsius.
4. d) 94 degrees Celsius.

Answer: c.

Question 33. In micro-injection, recombinant DNA is directly injected into what part of an animal cell?

1. a) Cell wall.
2. b) Cytoplasm.
3. c) Nucleus.
4. d) Mitochondria.

Answer: c.

Question 34. Which method of gene transfer involves bombarding cells with high-velocity microparticles of gold or tungsten coated with DNA?

1. a) Micro-injection.
2. b) Biolistics (Gene gun).
3. c) Electroporation.
4. d) Heat shock.

Answer: b.

Question 35. What enzyme is used to break open bacterial cells to release their DNA along with other macromolecules?

1. a) Chitinase.
2. b) Cellulase.
3. c) Lysozyme.
4. d) Protease.

Answer: c.

Question 36. During the isolation of genetic material, which enzyme is added to remove RNA?

1. a) Deoxyribonuclease.
2. b) Ribonuclease (RNase).
3. c) Protease.
4. d) Lipase.

Answer: b.

Question 37. In the final step of DNA isolation, purified DNA precipitates out after the addition of which chilled substance?

1. a) Ethanol.
2. b) Methanol.
3. c) Isopropanol.
4. d) Chloroform.

Answer: a.

Question 38. The collection of fine threads of precipitated DNA from a suspension using a glass rod is called what?

1. a) Elution.
2. b) Spooling.
3. c) Annealing.
4. d) Extension.

Answer: b.

Question 39. What does PCR stand for in the context of biotechnology?

1. a) Protein Chain Reaction.
2. b) Polymerase Chain Reaction.
3. c) Primary Cellular Respiration.
4. d) Polynucleotide Copying Reaction.

Answer: b.

Question 40. What are the three basic steps of a PCR cycle in correct order?

1. a) Annealing, Denaturation, Extension.
2. b) Denaturation, Extension, Annealing.
3. c) Denaturation, Annealing, Extension.
4. d) Extension, Denaturation, Annealing.

Answer: c.

Question 41. At what temperature does the denaturation step of PCR typically occur?

1. a) 50-60 degrees Celsius.
2. b) 72 degrees Celsius.
3. c) 94-96 degrees Celsius.
4. d) 37 degrees Celsius.

Answer: c.

Question 42. Thermus aquaticus is the source of which crucial enzyme used in PCR?

1. a) EcoRI.
2. b) DNA ligase.
3. c) Taq polymerase.
4. d) Reverse transcriptase.

Answer: c.

Question 43. Why is Taq polymerase used in PCR instead of regular DNA polymerase from E. coli?

1. a) It works faster than other polymerases.
2. b) It is thermostable and remains active during the high-temperature denaturation step.
3. c) It requires no primers to initiate synthesis.
4. d) It can synthesize DNA in the 3' to 5' direction.

Answer: b.

Question 44. If a recombinant gene is expressed in a heterologous host, the resulting protein is called a/an:

1. a) Transgenic protein.
2. b) Recombinant protein.
3. c) Homologous protein.
4. d) Chimeric protein.

Answer: b.

Question 45. To produce large quantities of a desired recombinant protein, which continuous culture system is frequently used?

1. a) Batch culture.
2. b) Bioreactors.
3. c) Petri dishes.
4. d) Gel electrophoresis.

Answer: b.

Question 46. What is the primary advantage of a continuous culture system over a batch culture?

1. a) It requires less nutrient medium.
2. b) It maintains the cells in their physiologically most active log/exponential phase.
3. c) It is completely free from the risk of contamination.
4. d) It eliminates the need for downstream processing.

Answer: b.

Question 47. Which type of bioreactor features a curved base to facilitate the mixing of the reactor contents?

1. a) Simple stirred-tank bioreactor.
2. b) Sparged stirred-tank bioreactor.
3. c) Airlift bioreactor.
4. d) Fluidized bed bioreactor.

Answer: a.

Question 48. In a sparged stirred-tank bioreactor, what is the primary purpose of sparging sterile air through the culture?

1. a) To decrease the temperature of the culture.
2. b) To increase the surface area for oxygen transfer.
3. c) To break open the cells for product extraction.
4. d) To prevent the growth of aerobic bacteria.

Answer: b.

Question 49. Downstream processing includes which two primary steps before the product is ready for marketing?

1. a) Separation and purification.
2. b) Denaturation and annealing.
3. c) Fermentation and packaging.
4. d) Clinical trials and mutation.

Answer: a.

Question 50. According to NEET PYQ trends, downstream processing is considered incomplete without which final step for products intended for human use?

1. a) Gel electrophoresis.
2. b) Strict quality control testing and clinical trials.
3. c) Spooling of the product.
4. d) Insertional inactivation.

Answer: b.

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