🧬 Biotechnology and Its Applications NEET Test

🧬 Biotechnology and Its Applications NEET Test

📋 Test Highlights:

• 🧠 NEET-Style MCQs: Practice application-based questions and PYQs
• 🌿 Topics Covered:
  • 🧬 Genetic Engineering & rDNA Technology
  • 🌱 Biotechnological Applications in Agriculture
  • 💊 Medical Biotechnology & Gene Therapy
  • ⚖️ Bioethics & Biosafety
• 📈 Performance Analysis: Get instant feedback and detailed explanations for every answer
•  

  Results

  

  

  

  #1. The first artificial recombinant DNA molecule was created by:

  Linking of gene encoding antibiotic resistance with a native plasmid of Salmonella typhimurium.

  Linking of gene encoding fertility factor with a native plasmid of E. coli.

  Linking of gene encoding β-galactosidase with a native plasmid of Agrobacterium tumefaciens.

  Linking of gene encoding lactase with a native plasmid of E. coli.

  Answer: (1) Linking of gene encoding antibiotic resistance with a native plasmid of Salmonella typhimurium.

  Explanation: The first recombinant DNA molecule was created by Paul Berg in 1972 by combining a gene encoding antibiotic resistance with the plasmid of Salmonella typhimurium.

  #2. . Which of the following is the most accepted definition of biotechnology by the European Federation of Biotechnology (EFB)?

  Maintenance of sterile ambiance for enabling growth of desired microbe/eukaryotic cell in large quantities.

  Technique of using live organisms or enzymes from organisms to produce products and processes useful to animals.

  Process which uses genetically engineered animals only on a large scale for the benefit of mankind.

  The integration of natural science and organisms, cells, parts thereof, and molecular analogies for products and services.

  Answer: (4) The integration of natural science and organisms, cells, parts thereof, and molecular analogies for products and services.

  Explanation: This definition emphasizes biotechnology’s broad scope, involving the integration of natural sciences and organisms for the development of products and services.

  #3. Which of the following statements are true about scientist Paul Berg? • (a) He is the Father of genetic engineering. • (b) He transferred the gene of the SV40 virus into E. coli. • (c) He got the Nobel Prize in chemistry in 1980. • (d) He developed hybridoma technology for the production of monoclonal antibodies.

  (a) and (b)

  (b) and (c)

  (c) and (d)

  (a), (b) and (c)

  Answer: (4) (a), (b), and (c)

  Explanation: Paul Berg is credited with pioneering genetic engineering by transferring genes, including that of the SV40 virus, into E. coli and won the Nobel Prize in Chemistry in 1980.

  #4. Select the option that is incorrect with respect to traditional hybridization.

  It is a procedure extensively used in plant breeding.

  It often leads to the inclusion of undesirable genes.

  It involves selective inclusion and multiplication of desired genes only.

  It enabled qualitative and quantitative improvement in food production.

  Answer: (3) It involves selective inclusion and multiplication of desired genes only.

  Explanation: Traditional hybridization may not always result in the selective inclusion of desired genes and can unintentionally incorporate unwanted genes.

  #5. Which of the following is true about the European Federation of Biotechnology (EFB) definition of biotechnology?

  It includes the traditional view.

  It includes modern molecular biotechnology.

  The definition is the integration of natural science and organisms, cells, parts, thereof, and molecular analogues for products and services.

  All of these.

  Explanation: The definition provided by the EFB encompasses both traditional and modern biotechnology, integrating various scientific domains for product and service development.

  #6. A suitable method of transformation with recombinant DNA for plants in which cells are bombarded with high-velocity micro-particles of gold or tungsten coated with DNA is:

  Biolistics.

  Microinjection.

  Gene gun.

  Both (1) and (3).

  Answer: (4) Both (1) and (3).

  Explanation: Biolistics and the gene gun both involve the use of high-velocity particles coated with DNA for genetic transformation in plants.

  #7. Mark the correct statement.

  The insertional inactivation in biotechnology is a term for inactivation of gene in chromosomal DNA of bacterial cells.

  The cloning site of plasmid is the site where insertion of foreign DNA is done.

  Today, transgenic models exist for Down’s syndrome.

  The process of complete fermentation in a bioreactor is called downstream processing.

  Answer: (2) The cloning site of plasmid is the site where insertion of foreign DNA is done.

  Explanation: The cloning site in a plasmid is specifically designed for inserting foreign DNA during recombinant DNA technology processes

  #8. In genetic engineering, a DNA segment (gene) of interest is transferred into the host cell through a vector. Consider the following four agents (a) – (d) and select the correct option of which one or more of these can be used as vector/vectors. • (a) A bacterium • (b) Plasmid • (c) Plasmodium • (d) Bacteriophage

  (a) and (c)

  (b) and (d)

  (a), (b), and (d)

  Only (a)

  Answer: (2) (b) and (d)

  Explanation: Plasmids and bacteriophages are commonly used as vectors in genetic engineering to transfer DNA into host cells.

  #9. When a recombinant DNA is inserted within the coding sequence of an enzyme, β-galactosidase:

  This results in the inactivation of the enzyme.

  This is called insertional inactivation.

  The colonies do not produce any color

  All of these.

  Answer: (4) All of these.

  Explanation: Insertion of recombinant DNA into the coding sequence of β-galactosidase results in insertional inactivation, leading to colorless colonies.

  #10. Select the incorrect statement:

  More than 900 restriction enzymes have been isolated from over 230 strains of bacteria.

  In the year 1963, two enzymes responsible for restricting the growth of bacteriophage in Escherichia coli were isolated.

  Some key tools for recombinant DNA technology are restriction enzyme, polymerase enzyme, ligase, vectors, and host root organisms.

  EcoRI cuts the DNA between bases A and T only when the sequence GAATTC is present in the DNA.

  Answer: (3) Some key tools for recombinant DNA technology are restriction enzyme, polymerase enzyme, ligase, vectors, and host root organisms.

  Explanation: This option incorrectly refers to “host root organisms” instead of “host organisms” as tools in recombinant DNA technology.

  #11. Which of the following statements about restriction enzymes is true?

  Restriction enzymes are used to cleave DNA molecules at specific locations.

  They are naturally occurring enzymes found in bacteria.

  They play a critical role in defending bacteria against viruses.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Restriction enzymes are naturally found in bacteria and are involved in defense mechanisms against viruses. They cleave DNA at specific sequences.

  #12. Which is the most commonly used method for introducing foreign genes into a plant cell?

  Agrobacterium-mediated transformation.

  Electroporation.

  Gene gun method.

  Microinjection.

  Answer: (1) Agrobacterium-mediated transformation.

  Explanation: Agrobacterium tumefaciens is the most commonly used tool for transferring genes into plants, exploiting its natural ability to transfer DNA.

  #13. The process of introducing a foreign gene into a living cell is called:

  Cloning.

  Transformation.

  Mutation.

  Transfection.

  Answer: (2) Transformation.

  Explanation: Transformation is the process of introducing foreign DNA into a cell, which may lead to the expression of the foreign gene.

  #14. What is the role of ligase in recombinant DNA technology?

  It cuts the DNA into fragments.

  t joins the DNA fragments together.

  It replicates the DNA.

  It binds the plasmid to the host cell.

  Explanation: Ligase is an enzyme used to join DNA fragments by forming phosphodiester bonds between them.

  #15. Which of the following methods is used to insert recombinant DNA into a host cell without using a vector?

  Electroporation.

  Gene gun.

  Microinjection.

  All of the above.

  Answer: (4) All of the above.

  Explanation: All these methods (electroporation, gene gun, and microinjection) can be used to insert recombinant DNA into host cells without the need for a vector.

  #16. The process of producing identical copies of a gene or organism is called:

  Cloning.

  Recombinant DNA technology.

  Gene mapping.

  Electroporation.

  Answer: (1) Cloning.

  Explanation: Cloning refers to the process of producing identical copies of a gene, cell, or organism.

  #17. Which of the following is used as a marker gene in recombinant DNA technology?

  Antibiotic resistance gene.

  Green fluorescent protein (GFP) gene.

  LacZ gene.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Marker genes such as antibiotic resistance, GFP, and LacZ are used to identify and select successfully transformed cells.

  #18. What is the purpose of using a plasmid in genetic engineering?

  To insert foreign DNA into a host organism.

  To replicate foreign DNA inside the host cell.

  To express foreign proteins in the host.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Plasmids are used as vectors in genetic engineering to carry foreign DNA, replicate it inside the host cell, and express proteins encoded by the foreign DNA.

  #19. Which of the following is NOT a feature of a plasmid vector?

  Origin of replication.

  Selectable marker gene.

  Inability to replicate in bacterial cells.

  Multiple cloning sites.

  Answer: (3) Inability to replicate in bacterial cells.

  Explanation: Plasmids are designed to replicate in bacterial cells, making them suitable for cloning foreign DNA.

  #20. In genetic engineering, the process of selecting transformed cells based on their ability to grow in the presence of an antibiotic is known as:

  Selection.

  Screening.

  Transformation.

  Cloning.

  Answer: (1) Selection.

  Explanation: Selection refers to the process of identifying transformed cells that carry a specific genetic modification, typically using an antibiotic resistance marker.

  #21. Which of the following is an example of a genetically modified organism (GMO)?

  Bt cotton.

  Golden rice.

  Roundup-ready soybeans.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Bt cotton, golden rice, and roundup-ready soybeans are all examples of genetically modified organisms designed for specific agricultural benefits.

  #22. The principle of molecular cloning involves:

  Cutting the DNA into small fragments.

  Inserting the DNA fragment into a vector.

  Transferring the vector into a host organism.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Molecular cloning involves cutting DNA into fragments, inserting those fragments into vectors, and transferring the recombinant vector into a host organism for expression or replication.

  #23. What does PCR (Polymerase Chain Reaction) primarily achieve?

  Amplifying a specific DNA sequence.

  Repairing damaged DNA.

  Cutting DNA at specific locations.

  Inserting foreign genes into DNA.

  Answer: (1) Amplifying a specific DNA sequence.

  Explanation: PCR is a technique used to amplify specific DNA sequences to create many copies for further study or use.

  #24. Which of the following is true about transgenic animals?

  They are genetically modified to express desired traits.

  They are created by introducing foreign genes into their genome.

  They are used for producing proteins or for research purposes.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Transgenic animals are genetically engineered to express specific traits, often for research or biopharmaceutical purposes.

  #25. Which of the following is an application of recombinant DNA technology?

  Production of insulin.

  Gene therapy.

  Production of vaccines.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Recombinant DNA technology is used in producing insulin, gene therapy, and vaccines, among other applications.

  #26. Which of the following is NOT a function of the Agrobacterium tumefaciens in genetic engineering?

  It acts as a natural vector for gene transfer in plants.

  It contains a plasmid known as Ti plasmid, which can transfer genes into plant cells.

  It directly transfers its DNA into animal cells.

  It causes crown gall disease in plants, which helps in the gene transfer process.

  Answer: (3) It directly transfers its DNA into animal cells.

  Explanation: Agrobacterium tumefaciens is used to transfer DNA into plant cells, not animal cells, through its Ti plasmid.

  #27. Which of the following is NOT an example of a biotechnological application?

  Production of biofuels from algae.

  Production of human insulin by recombinant DNA technology.

  Use of CRISPR for gene editing in humans.

  Conventional cross-breeding of plants for improved traits.

  Answer: (4) Conventional cross-breeding of plants for improved traits.

  Explanation: Conventional cross-breeding is a traditional method and not a biotechnological application, which typically involves advanced genetic manipulation techniques.

  #28. A common tool used to cut DNA at specific locations for cloning or analysis is:

  Ligase.

  Polymerase.

  Restriction enzyme.

  Helicase.

  Answer: (3) Restriction enzyme.

  Explanation: Restriction enzymes are used to cut DNA at specific sequences, making them essential tools in genetic engineering.

  #29. In which of the following cases would you expect to use electroporation?

  Introducing a plasmid into plant cells.

  Introducing DNA into bacterial cells.

  Inserting a gene into animal cells.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Electroporation is used to introduce DNA into various cell types, including plant, bacterial, and animal cells, by creating temporary pores in the cell membrane.

  #30. What is the primary advantage of using genetically modified organisms (GMOs) in agriculture?

  Improved resistance to pests and diseases.

  Increased yield and nutritional value.

  Reduced environmental impact from the use of pesticides.

  All of the above.

  Answer: (4) All of the above.

  Explanation: GMOs are designed to offer benefits such as pest resistance, higher yields, improved nutritional content, and reduced reliance on harmful pesticides.

  #31. What does the term “bioreactor” refer to in biotechnology?

  A machine used to culture bacteria.

  A vessel where biological reactions are carried out.

  A tool for harvesting proteins from plants.

  A device used to clean wastewater.

  Answer: (2) A vessel where biological reactions are carried out.

  Explanation: A bioreactor is a vessel used in biotechnology to carry out controlled biological processes, such as fermentation or cell culture, for the production of proteins, enzymes, and other products.

  #32. The process of inserting recombinant DNA into a cell using a virus as a vector is called:

  Viral transduction.

  Electroporation.

  Microinjection.

  Transformation.

  Answer: (1) Viral transduction.

  Explanation: Viral transduction involves using a virus to introduce recombinant DNA into a host cell.

  #33. What is the purpose of the “lac operon” in bacterial genetic regulation?

  To control the metabolism of lactose.

  To regulate the expression of genes involved in antibiotic resistance.

  To produce energy from glucose.

  To protect against viruses.

  Answer: (1) To control the metabolism of lactose.

  Explanation: The lac operon is a regulatory system in bacteria that controls the breakdown of lactose when it is present in the environment.

  #34. Which of the following enzymes is used in PCR to amplify DNA?

  DNA polymerase.

  Restriction enzyme.

  Ligase.

  RNA polymerase.

  Answer: (1) DNA polymerase.

  Explanation: DNA polymerase is used in PCR to synthesize new strands of DNA by adding nucleotides to a DNA template strand.

  #35. Which of the following is NOT an example of a genetically modified crop?

  Bt cotton.

  Roundup-ready soybeans.

  Golden rice.

  Wheat produced by conventional cross-breeding.

  Answer: (4) Wheat produced by conventional cross-breeding.

  Explanation: Genetically modified crops involve direct genetic modification, whereas conventional cross-breeding does not.

  #36. What is the purpose of the green fluorescent protein (GFP) in genetic engineering?

  To mark cells that have been successfully transformed.

  To help in gene expression analysis.

  To allow researchers to visualize cells under UV light.

  All of the above.

  Answer: (4) All of the above.

  Explanation: GFP is used as a marker in genetic engineering to track successful transformation, analyze gene expression, and visualize cells under UV light.

  #37. What is the term “transfection” used for in genetic engineering?

  The process of inserting DNA into bacterial cells.

  The process of inserting DNA into animal cells.

  The process of cloning an organism.

  The process of extracting DNA from cells.

  Answer: (2) The process of inserting DNA into animal cells.

  Explanation: Transfection refers to the process of introducing DNA into animal cells, commonly used in gene therapy and research.

  #38. Which of the following is a benefit of using CRISPR-Cas9 in genetic engineering?

  Precise editing of specific genes.

  Ability to target multiple genes simultaneously.

  Less expensive compared to other gene-editing techniques.

  All of the above.

  Answer: (4) All of the above.

  Explanation: CRISPR-Cas9 is a powerful and precise gene-editing tool that allows targeted gene modifications and is cost-effective compared to other techniques.

  #39. In genetic engineering, a gene that confers resistance to an antibiotic is used as a:

  Reporter gene.

  Marker gene.

  Selectable marker gene.

  Expression gene.

  Answer: (3) Selectable marker gene.

  Explanation: A selectable marker gene, such as an antibiotic resistance gene, allows researchers to identify and select transformed cells in a culture.

  #40. Which of the following is the process of transferring recombinant DNA into plant cells using a gene gun?

  Biolistics.

  Electroporation.

  Agrobacterium-mediated transformation.

  Particle bombardment.

  Answer: (1) Biolistics.

  Explanation: Biolistics, or particle bombardment, uses high-velocity micro-particles coated with DNA to transfer genes into plant cells.

  #41. What is the role of a vector in genetic engineering?

  To carry foreign DNA into a host organism.

  To replicate foreign DNA inside the host cell.

  To express the foreign gene in the host organism.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Vectors are used to carry foreign DNA, replicate it in the host cell, and express the desired gene.

  #42. Which of the following is a product of recombinant DNA technology used in medical applications?

  Insulin.

  Growth hormone.

  Vaccines.

  All of the above.

  Answer: (4) All of the above.

  Explanation: Recombinant DNA technology is used to produce therapeutic products such as insulin, growth hormone, and vaccines.

  #43. Arrange the following process in the sequence it is used in rDNA technology. (a) Isolation of DNA (b) Fragmentation of DNA by RE (c) Isolation of desired DNA fragment (d) Ligation of DNA fragment into vector (e) Transferring r-DNA into host (f ) Culturing host cells in a medium at large scale (g) Extraction of the desired product

  (a), (b), (c), (d), (e), (f ), (g)

  (a), (b), (c), (d), (f ), (e), (g)

  (b), (a), (c), (d), (e), (f ), (g)

  (a), (b), (c), (e), (d), (f ), (g)

  The correct answer is:

  (1) (a), (b), (c), (d), (e), (f ), (g)

  Explanation:
  In recombinant DNA (rDNA) technology, the processes are followed in a specific order:

  1. Isolation of DNA – First, DNA is isolated from the organism of interest.
  2. Fragmentation of DNA by restriction enzymes (RE) – The isolated DNA is then fragmented into smaller pieces using restriction enzymes.
  3. Isolation of desired DNA fragment – The fragment that contains the gene of interest is isolated.
  4. Ligation of DNA fragment into vector – The desired DNA fragment is then inserted into a vector (e.g., plasmid) using DNA ligase.
  5. Transferring r-DNA into host – The recombinant DNA (rDNA) is transferred into a host organism (usually a bacterium).
  6. Culturing host cells in a medium at large scale – The host cells are cultured to propagate the recombinant DNA.
  7. Extraction of the desired product – Finally, the desired product (e.g., protein) is extracted from the host cells.

  #44. Manipulation in genes has been made possible because of:

  Discovery of restriction endonuclease

  Development of method for production of rDNA

  ) Development of method for production of the desired gene

  All of these

  Answer: (4) All of these
  Explanation: All the mentioned factors contribute to the advancement of gene manipulation. Restriction enzymes help in cutting DNA, recombinant DNA technology enables combining genes from different organisms, and the production of desired genes is essential for creating transgenic organisms.

  #45. What is the main principle behind rDNA technology?

  Gene manipulations

  DNA amplification

  Density gradient centrifugation

  Mutational breeding

  Answer: (1) Gene manipulations
  Explanation: Recombinant DNA technology focuses on manipulating genes by inserting foreign DNA into a host organism to express new traits.

  #46. In isolation of genetic material (DNA) from the nucleus, the RNA can be removed by ribonuclease and protein by protease. Purified DNA then precipitates after the addition of _______.

  CaCl2

  Ether

  Chilled ethanol

  Acetic acid

  Answer: (3) Chilled ethanol
  Explanation: Chilled ethanol causes DNA to precipitate, allowing it to be separated from other cellular components.

  #47. If any protein-encoding gene is expressed in a _____________ host, it is called a _________ protein. Options:

  Homologous; recombinant

  Heterologous; recombinant

  Heterologous; non-recombinant

  Homologous; non-recombinant

  Answer: (2) Heterologous; recombinant
  Explanation: A heterologous host refers to a host organism that is different from the source of the gene, and when it expresses the gene, the protein is considered recombinant.

  #48. Electroporation involves:

  Promotion of seed germination by induced inhibition of water with electric current

  Making transient pores in cell membrane to facilitate entry of gene constructs

  Purification of saline water with the help of an artificial membrane

  Passage of sucrose through sieve pores by electro osmosis

  Answer: (2) Making transient pores in cell membrane to facilitate entry of gene constructs
  Explanation: Electroporation uses electric pulses to create temporary pores in the cell membrane, allowing foreign DNA to enter the cell.

  #49. The significance of heat shock method in bacterial transformation is to facilitate: Options:

  Binding of DNA to the cell wall

  Uptake of DNA through membrane transport proteins

  Uptake of DNA through transient pores in the bacterial cell wall

  Expression of antibiotic resistance gene

  Answer: (3) Uptake of DNA through transient pores in the bacterial cell wall
  Explanation: Heat shock creates temporary pores in the bacterial cell wall, allowing the entry of foreign DNA during transformation.

  #50. The role of DNA ligase in the construction of a recombinant DNA molecule involves:

  Formation of a phosphodiester bond between two DNA fragments

  Formation of hydrogen bonds between sticky ends of DNA fragments

  Ligation of all purine and pyrimidine bases

  None of these

  Answer: (1) Formation of a phosphodiester bond between two DNA fragments
  Explanation: DNA ligase is an enzyme that joins two DNA fragments by forming a phosphodiester bond, facilitating the creation of recombinant DNA molecules.

  #51. Which of the following enzymes is used to cut DNA at specific sequences?

  Ligase

  Restriction endonuclease

  DNA polymerase

  RNA polymerase

  Answer: (2) Restriction endonuclease
  Explanation: Restriction endonucleases are enzymes that cut DNA at specific sequences, making them crucial for rDNA technology.

  #52. What is the function of the plasmid vector in recombinant DNA technology?

  To introduce the foreign gene into the host cell

  To amplify the foreign gene inside the host cell

  To protect the foreign gene from degradation

  All of these

  Answer: (4) All of these
  Explanation: Plasmid vectors serve multiple roles: they carry the foreign gene into the host cell, replicate the gene within the host, and help protect the gene from degradation.

  #53. Which of the following is NOT a method for transferring recombinant DNA into host cells?

  Electroporation

  Gene gun method

  Viral vectors

  Phototransfection

  Answer: (4) Phototransfection
  Explanation: Phototransfection is not a common method for transferring recombinant DNA. The other methods listed (electroporation, gene gun, and viral vectors) are widely used in gene transfer.

  #54. In the context of genetic engineering, what does ‘transformation’ refer to?

  The uptake of foreign DNA by a cell

  The modification of an organism’s phenotype

  The insertion of foreign genes into the genome of an organism

  The cloning of genetically modified organisms

  Answer: (1) The uptake of foreign DNA by a cell
  Explanation: Transformation is the process by which a cell takes up foreign DNA from its surroundings, which can then be integrated into its genome.

  #55. In recombinant DNA technology, what is the role of the antibiotic resistance gene?

  To kill unwanted cells

  To allow the identification of successfully transformed cells

  To enhance the growth rate of the transformed cells

  To protect the host from external contamination

  Answer: (2) To allow the identification of successfully transformed cells
  Explanation: The antibiotic resistance gene serves as a selectable marker, allowing the identification of cells that have successfully incorporated the recombinant DNA.

  #56. What is the key difference between a cloning vector and an expression vector?

  A cloning vector only carries DNA for replication, while an expression vector includes sequences for gene expression.

  A cloning vector can replicate but not express genes, while an expression vector can only express genes.

  A cloning vector is used for sequencing, while an expression vector is used for PCR.

  There is no difference between the two.

  Answer: (1) A cloning vector only carries DNA for replication, while an expression vector includes sequences for gene expression.
  Explanation: Cloning vectors are designed to carry and replicate DNA, while expression vectors are designed to express the cloned gene within a host cell.

  #57. Which of the following is used to detect the presence of a specific gene in a recombinant DNA molecule?

  Gel electrophoresis

  Southern blotting

  PCR

  All of the above

  Answer: (4) All of the above
  Explanation: Gel electrophoresis, Southern blotting, and PCR are all techniques used to detect and analyze specific genes in recombinant DNA molecules.

  #58. Which of the following is a characteristic of a good cloning vector?

  Small size and ability to replicate independently

  High capacity to insert foreign genes

  Presence of multiple cloning sites

  All of the above

  Answer: (4) All of the above
  Explanation: A good cloning vector is small, capable of independent replication, and has multiple cloning sites to accommodate the insertion of foreign genes.

  #59. In PCR, what is the purpose of the denaturation step?

  To amplify the DNA sequence

  To separate the double-stranded DNA into single strands

  To extend the primers for replication

  To add nucleotides to the growing DNA strand

  Answer: (2) To separate the double-stranded DNA into single strands
  Explanation: Denaturation involves heating the DNA to break the hydrogen bonds between the strands, producing single-stranded DNA templates for amplification.

  #60. Which of the following enzymes is responsible for joining two DNA fragments together?

  DNA polymerase

  DNA ligase

  RNA polymerase

  Reverse transcriptase

  Answer: (2) DNA ligase
  Explanation: DNA ligase is the enzyme that joins two DNA fragments together by forming phosphodiester bonds between the nucleotide ends.

  #61. Which of the following techniques can be used to amplify a specific DNA segment?

  Electrophoresis

  Polymerase Chain Reaction (PCR)

  Restriction digestion

  Southern blotting

  Answer: (2) Polymerase Chain Reaction (PCR)
  Explanation: PCR is a technique used to amplify specific DNA segments by repeated cycles of denaturation, annealing, and extension.

  #62. What is the role of a restriction enzyme in recombinant DNA technology?

  It cuts DNA at specific sequences

  It ligates DNA fragments together

  It copies the inserted DNA

  It synthesizes RNA from DNA

  Answer: (1) It cuts DNA at specific sequences
  Explanation: Restriction enzymes recognize and cut DNA at specific sequences, allowing the insertion of foreign genes into vectors or other DNA molecules.

  #63. In recombinant DNA technology, which of the following is used to insert foreign DNA into a host cell?

  Ligase

  Heat shock

  Electroporation

  All of the above

  Answer: (4) All of the above
  Explanation: Heat shock, electroporation, and ligase can all be used to insert foreign DNA into host cells, each through different methods.

  #64. Which of the following is true about bacterial plasmids used in recombinant DNA technology?

  Plasmids can replicate independently of the bacterial chromosome

  Plasmids are large pieces of linear DNA

  Plasmids are only used for cloning human genes

  Plasmids are not used to transform bacterial cells

  Answer: (1) Plasmids can replicate independently of the bacterial chromosome
  Explanation: Plasmids are small, circular DNA molecules that replicate independently of the bacterial chromosome, making them useful in cloning and gene expression.

  #65. Which of the following can be a result of successful recombinant DNA technology?

  Production of insulin

  Development of genetically modified crops

  Synthesis of human growth hormone

  All of the above

  Answer: (4) All of the above
  Explanation: Recombinant DNA technology has led to the production of important proteins like insulin and human growth hormone, as well as genetically modified organisms for agricultural purposes.

  #66. In recombinant DNA technology, what is the purpose of a bacterial transformation?

  To introduce a new gene into a bacterium

  To replicate a gene outside the cell

  To increase the rate of gene expression

  To modify the bacterial cell’s genome

  Answer: (1) To introduce a new gene into a bacterium
  Explanation: Transformation is the process of introducing foreign DNA into a bacterial cell, allowing the bacterium to express or replicate the foreign gene.

  #67. Which of the following is a key feature of a plasmid vector in recombinant DNA technology?

  It can carry large fragments of foreign DNA

  It contains a selectable marker

  It is linear in structure

  It lacks a promoter for gene expression

  Answer: (2) It contains a selectable marker
  Explanation: Plasmid vectors often contain a selectable marker (e.g., antibiotic resistance) that allows researchers to identify cells that have successfully taken up the plasmid.

  #68. Which of the following is true about a restriction enzyme?

  It can bind to any sequence of DNA

  It cuts DNA randomly

  It recognizes specific sequences and cuts DNA at those sites

  It is only used in bacterial cells

  Answer: (3) It recognizes specific sequences and cuts DNA at those sites
  Explanation: Restriction enzymes are highly specific and recognize particular sequences in DNA to cut at those sites, making them crucial in gene manipulation.

  #69. What is a common use of gel electrophoresis in recombinant DNA technology?

  o amplify DNA sequences

  To separate DNA fragments by size

  To insert genes into plasmids

  To clone genes

  Answer: (2) To separate DNA fragments by size
  Explanation: Gel electrophoresis is used to separate DNA fragments based on their size, allowing researchers to analyze and purify DNA fragments for further use.

  #70. Which of the following is a key difference between prokaryotic and eukaryotic cells in terms of genetic material?

  Prokaryotic cells have a nucleus, while eukaryotic cells do not

  Eukaryotic cells have circular DNA, while prokaryotic cells have linear DNA

  Prokaryotic cells lack a nucleus, while eukaryotic cells have a membrane-bound nucleus

  Eukaryotic cells have no genetic material, while prokaryotic cells do

  Answer: (3) Prokaryotic cells lack a nucleus, while eukaryotic cells have a membrane-bound nucleus
  Explanation: Prokaryotic cells do not have a membrane-bound nucleus, while eukaryotic cells contain a true nucleus where their genetic material is housed.

  #71. Which of the following best describes the role of RNA in protein synthesis?

  RNA carries the genetic instructions from the DNA to the ribosomes

  RNA is the blueprint for forming the DNA double helix

  RNA translates the protein into an amino acid sequence

  RNA stores the genetic information for future generations

  Answer: (1) RNA carries the genetic instructions from the DNA to the ribosomes
  Explanation: mRNA (messenger RNA) carries genetic instructions from the DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are synthesized.

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