ROUTERA


Chapter 11 BiotechnologyPrinciples and processes

Class 12th Biology Chapter MCQs


1. What is the first step in genetic engineering?

  • A) Transformation
  • B) Selection
  • C) Isolation of the gene of interest
  • D) Cloning

Answer: C
Explanation: The first step in genetic engineering is the isolation of the gene of interest from the organism's genome.


2. Which of the following is used as a vector in gene cloning?

  • A) Plasmids
  • B) Ribosomes
  • C) Cell wall
  • D) Mitochondria

Answer: A
Explanation: Plasmids are commonly used as vectors in gene cloning because they are small, circular pieces of DNA capable of carrying foreign genes.


3. What is the role of restriction enzymes in biotechnology?

  • A) They bind to the target DNA
  • B) They cut the DNA at specific sites
  • C) They replicate the DNA
  • D) They produce mRNA

Answer: B
Explanation: Restriction enzymes are used to cut DNA at specific sites to create sticky or blunt ends, which are necessary for the insertion of foreign DNA.


4. Which enzyme is used to join the foreign DNA fragment with the vector DNA?

  • A) DNA ligase
  • B) Reverse transcriptase
  • C) RNA polymerase
  • D) Ligase

Answer: A
Explanation: DNA ligase is used to join the foreign DNA fragment to the vector DNA by forming phosphodiester bonds between them.


5. What is the process of introducing foreign DNA into a host cell called?

  • A) Transformation
  • B) Transfection
  • C) Transduction
  • D) Cloning

Answer: A
Explanation: Transformation is the process of introducing foreign DNA into a host cell, often bacteria, to create genetically modified organisms (GMOs).


6. Which of the following is an example of a recombinant DNA product?

  • A) Insulin
  • B) Hydrogen
  • C) Oxygen
  • D) Water

Answer: A
Explanation: Insulin is a commonly used recombinant DNA product that is produced by genetically engineered bacteria.


7. What is the primary use of the Agrobacterium tumefaciens in biotechnology?

  • A) Gene delivery system for plants
  • B) Protein synthesis
  • C) Genetic modification of bacteria
  • D) Fermentation of alcohol

Answer: A
Explanation: Agrobacterium tumefaciens is used as a gene delivery system for introducing foreign genes into plants, particularly for creating transgenic plants.


8. Which of the following is a process used for amplifying DNA?

  • A) PCR
  • B) Electrophoresis
  • C) Cloning
  • D) Transfection

Answer: A
Explanation: Polymerase chain reaction (PCR) is a technique used for amplifying DNA by creating millions of copies of a specific DNA segment.


9. Which of the following is NOT a type of cloning vector?

  • A) Plasmids
  • B) Bacteriophages
  • C) Phagocytes
  • D) Cosmids

Answer: C
Explanation: Phagocytes are not used as cloning vectors. Cloning vectors include plasmids, bacteriophages, and cosmids.


10. What is the purpose of the selectable marker in gene cloning?

  • A) To insert the foreign gene into the host DNA
  • B) To kill the host cell
  • C) To allow the identification of transformed cells
  • D) To cleave the DNA

Answer: C
Explanation: Selectable markers help identify transformed cells that have taken up the recombinant DNA, usually by conferring resistance to an antibiotic.


11. Which of the following is used to identify specific DNA sequences in a sample?

  • A) Restriction enzymes
  • B) Nucleotides
  • C) DNA probes
  • D) Ligases

Answer: C
Explanation: DNA probes are used to identify specific DNA sequences by hybridizing to complementary sequences in the sample.


12. What is the main function of reverse transcriptase in biotechnology?

  • A) Synthesize DNA from RNA
  • B) Synthesize RNA from DNA
  • C) Cut DNA into fragments
  • D) Replicate DNA

Answer: A
Explanation: Reverse transcriptase synthesizes DNA from RNA, a process used to create complementary DNA (cDNA) from mRNA.


13. Which of the following processes involves the transfer of a gene into a plant cell using a biolistic method?

  • A) Electroporation
  • B) Gene gun
  • C) Transformation
  • D) Transduction

Answer: B
Explanation: The gene gun (biolistic method) involves shooting DNA-coated gold or tungsten particles into plant cells for gene transfer.


14. Which of the following is a common application of genetically modified organisms (GMOs)?

  • A) Production of biogas
  • B) Treatment of diseases
  • C) Production of transgenic plants
  • D) Water purification

Answer: C
Explanation: Genetically modified organisms (GMOs) are often used in the production of transgenic plants with desirable traits, such as resistance to pests or diseases.


15. Which of the following is the function of Taq polymerase in PCR?

  • A) To synthesize RNA
  • B) To amplify DNA at high temperatures
  • C) To cut DNA at specific sites
  • D) To join DNA fragments

Answer: B
Explanation: Taq polymerase is used in PCR to amplify DNA because it can withstand high temperatures required for denaturation of the DNA.


16. Which of the following is a technique used to separate DNA fragments based on their size?

  • A) Gel electrophoresis
  • B) PCR
  • C) Gene transfer
  • D) Cloning

Answer: A
Explanation: Gel electrophoresis separates DNA fragments by size, with smaller fragments moving faster through the gel.


17. Which of the following organisms is used to produce human insulin through recombinant DNA technology?

  • A) Escherichia coli
  • B) Saccharomyces cerevisiae
  • C) Bacillus thuringiensis
  • D) Rhizobium

Answer: A
Explanation: Escherichia coli is used to produce human insulin by inserting the human insulin gene into its genome through recombinant DNA technology.


18. Which of the following is used to produce the first genetically modified crop, Bt cotton?

  • A) Bacillus thuringiensis
  • B) Rhizobium
  • C) Escherichia coli
  • D) Streptococcus

Answer: A
Explanation: Bacillus thuringiensis is used to produce Bt cotton, which contains a gene from the bacterium that confers resistance to certain insect pests.


19. Which of the following is a major concern with the use of genetically modified organisms (GMOs)?

  • A) Increased biodiversity
  • B) Spread of antibiotic resistance genes
  • C) Improved yield of crops
  • D) Increased pollution

Answer: B
Explanation: One major concern with GMOs is the spread of antibiotic resistance genes, which could transfer to harmful bacteria.


20. What is the role of DNA polymerase in the process of DNA replication?

  • A) To add nucleotides to the growing DNA strand
  • B) To unwind the DNA helix
  • C) To cut the DNA strands
  • D) To create the primer

Answer: A
Explanation: DNA polymerase adds nucleotides to the growing DNA strand during DNA replication.


21. Which of the following is a plant-based biotechnology product?

  • A) Golden rice
  • B) Human insulin
  • C) E. coli-derived drugs
  • D) Human growth hormone

Answer: A
Explanation: Golden rice is a genetically modified crop that contains increased levels of vitamin A (beta-carotene), developed through biotechnology.


22. Which of the following is a direct application of recombinant DNA technology in medicine?

  • A) Antibiotic production
  • B) Insulin production
  • C) Transgenic crops
  • D) Bioremediation

Answer: B
Explanation: Recombinant DNA technology is used for insulin production, which involves inserting the human insulin gene into bacteria for mass production.


23. What is the significance of the use of selectable markers in cloning vectors?

  • A) They kill the host cell
  • B) They help identify transformed cells
  • C) They provide nutrients to the host cell
  • D) They degrade the foreign DNA

Answer: B
Explanation: Selectable markers help in identifying cells that have been successfully transformed with the recombinant DNA.


24. What is a major advantage of using bioreactors in biotechnology?

  • A) Production of large quantities of products
  • B) Elimination of the need for cell culture
  • C) Prevention of contamination
  • D) They act as sources of antibiotics

Answer: A
Explanation: Bioreactors provide controlled conditions for the growth of microorganisms or cells, enabling the production of large quantities of desired products like enzymes or biofuels.


25. Which of the following is a potential use of transgenic animals?

  • A) Produce pharmaceuticals
  • B) Develop disease-resistant crops
  • C) Produce biofuels
  • D) Treat sewage

Answer: A
Explanation: Transgenic animals can be used to produce pharmaceuticals such as antibodies or proteins needed for medical treatments.


26. Which of the following is NOT a characteristic of biotechnology?

  • A) Gene manipulation
  • B) Use of microorganisms
  • C) Use of recombinant DNA technology
  • D) Chemical synthesis of proteins

Answer: D
Explanation: Chemical synthesis of proteins is not considered part of biotechnology. Biotechnology involves gene manipulation, the use of microorganisms, and recombinant DNA technology to produce desired products.


27. Which of the following is an example of a genetically modified organism used in agriculture?

  • A) Bt cotton
  • B) Brassica napus
  • C) Escherichia coli
  • D) Aspergillus niger

Answer: A
Explanation: Bt cotton is an example of a genetically modified organism (GMO) used in agriculture to resist pest damage due to the presence of a gene from Bacillus thuringiensis.


28. Which of the following is used in the process of polymerase chain reaction (PCR) to amplify DNA?

  • A) Helicase
  • B) DNA polymerase
  • C) Ligase
  • D) RNA polymerase

Answer: B
Explanation: DNA polymerase is used in PCR to amplify specific DNA sequences by adding nucleotides to the growing DNA strand.


29. Which of the following is true about the plasmid used as a vector in gene cloning?

  • A) It is a type of bacteriophage
  • B) It is a circular piece of DNA
  • C) It is always from a plant
  • D) It is a linear DNA fragment

Answer: B
Explanation: A plasmid is a circular piece of DNA found in bacteria and is used as a vector for gene cloning.


30. Which of the following techniques is used to transfer genetic material into a plant cell?

  • A) Electroporation
  • B) Gene gun
  • C) Microinjection
  • D) Transduction

Answer: B
Explanation: The gene gun is used to transfer genetic material into plant cells by firing DNA-coated particles into the plant cells.


31. Which of the following is used to identify a gene of interest in a recombinant DNA library?

  • A) DNA probe
  • B) Plasmid
  • C) Restriction enzyme
  • D) RNA polymerase

Answer: A
Explanation: DNA probes are used to identify a gene of interest in a recombinant DNA library by hybridizing with complementary sequences.


32. In recombinant DNA technology, what is the purpose of the "sticky ends"?

  • A) To prevent the insertion of foreign genes
  • B) To help DNA fragments adhere to each other
  • C) To separate the strands of DNA
  • D) To initiate transcription

Answer: B
Explanation: Sticky ends are overhangs that help DNA fragments adhere to each other by complementary base pairing, making the ligation process easier.


33. Which of the following organisms is used for the production of biogas?

  • A) Escherichia coli
  • B) Methanogenic bacteria
  • C) Saccharomyces cerevisiae
  • D) Bacillus thuringiensis

Answer: B
Explanation: Methanogenic bacteria are used in biogas production, as they break down organic matter and release methane.


34. What is the term for the process of obtaining a single colony from a single bacterium?

  • A) Cloning
  • B) Transformation
  • C) Subculturing
  • D) Conjugation

Answer: A
Explanation: Cloning is the process of obtaining a single colony of cells from a single bacterium or a single cell.


35. What is the purpose of using a "host cell" in recombinant DNA technology?

  • A) To cut the foreign DNA
  • B) To replicate the inserted gene
  • C) To provide a site for genetic recombination
  • D) To bind to the plasmid

Answer: B
Explanation: The host cell is used to replicate the inserted gene or produce the product encoded by the recombinant DNA.


36. Which of the following is an example of a secondary metabolite produced by microorganisms?

  • A) Antibiotics
  • B) Water
  • C) Glucose
  • D) DNA

Answer: A
Explanation: Antibiotics are secondary metabolites produced by microorganisms during their growth phase and are used to treat infections.


37. What is the function of the promoter sequence in recombinant DNA?

  • A) To select the host cell
  • B) To express the gene of interest
  • C) To cut the foreign DNA
  • D) To replicate the DNA

Answer: B
Explanation: The promoter sequence is used to initiate the expression of the gene of interest in recombinant DNA technology.


38. Which of the following is true about PCR?

  • A) It uses RNA as a template
  • B) It requires a special DNA polymerase
  • C) It is used to create recombinant DNA
  • D) It is a method of gene transfer

Answer: B
Explanation: PCR requires a special heat-stable DNA polymerase (Taq polymerase) to amplify DNA.


39. What is the function of the selectable marker gene in a plasmid?

  • A) To replicate the plasmid
  • B) To produce proteins of interest
  • C) To help select the transformed cells
  • D) To cut the target DNA

Answer: C
Explanation: The selectable marker gene helps to identify and select the transformed cells that carry the recombinant DNA.


40. Which of the following is used for the transformation of plant cells in genetic engineering?

  • A) Gene gun
  • B) Electroporation
  • C) Agrobacterium tumefaciens
  • D) Bioreactor

Answer: C
Explanation: Agrobacterium tumefaciens is widely used for the genetic transformation of plant cells, transferring foreign genes into them.


41. Which of the following techniques is used for gene editing in biotechnology?

  • A) CRISPR-Cas9
  • B) Gel electrophoresis
  • C) Northern blotting
  • D) RNA interference

Answer: A
Explanation: CRISPR-Cas9 is a powerful gene-editing tool used to precisely alter the DNA at specific locations in the genome.


42. Which of the following is true about the lac operon in genetic engineering?

  • A) It is used for gene expression in animals
  • B) It is used in bacterial transformation
  • C) It is a plant-based vector
  • D) It is a synthetic sequence created for gene silencing

Answer: B
Explanation: The lac operon is used in bacterial transformation for regulating the expression of genes, typically in Escherichia coli.


43. Which of the following is the main advantage of genetically modified crops?

  • A) Higher nutritional value
  • B) Increased pollution
  • C) Decreased yield
  • D) Reduced resistance to pests

Answer: A
Explanation: Genetically modified crops, like Golden Rice, offer higher nutritional value, as they can be engineered to contain additional vitamins or nutrients.


44. Which of the following is NOT an application of biotechnology in agriculture?

  • A) Pest-resistant crops
  • B) Herbicide-resistant crops
  • C) Production of biocontrol agents
  • D) Genetically modified crops for higher yield

Answer: C
Explanation: While biocontrol agents are used in agriculture, they are not directly an application of genetic engineering but rather involve the use of natural predators or pathogens to control pests.


45. What is a transgenic organism?

  • A) An organism with genes from the same species
  • B) An organism with genes from a different species
  • C) An organism with mutations
  • D) An organism used in cloning

Answer: B
Explanation: A transgenic organism is an organism that has genes from a different species inserted into its genome.


46. Which of the following is true about the use of antibiotics in recombinant DNA technology?

  • A) Antibiotics are used to kill host cells
  • B) Antibiotics are used as markers to select transformed cells
  • C) Antibiotics are used to prevent the transformation of cells
  • D) Antibiotics are used to synthesize proteins

Answer: B
Explanation: Antibiotics are used as selective markers in recombinant DNA technology to identify cells that have successfully incorporated recombinant DNA.


47. Which of the following is NOT an advantage of using microorganisms in biotechnology?

  • A) Fast growth
  • B) High yield of products
  • C) Complex synthesis of products
  • D) Ease of genetic manipulation

Answer: C
Explanation: Microorganisms are generally advantageous in biotechnology for fast growth, high yield, and genetic manipulation, but they cannot synthesize complex products as efficiently as other systems like plants or animals.


48. Which of the following vectors is commonly used in genetic transformation of plants?

  • A) pBR322
  • B) Ti plasmid
  • C) λ phage
  • D) Bacteriophage T4

Answer: B
Explanation: The Ti plasmid of Agrobacterium tumefaciens is commonly used in the genetic transformation of plants.


49. Which of the following is an application of biotechnology in the production of food?

  • A) Microbial fermentation
  • B) Water purification
  • C) Antibiotic production
  • D) Bioremediation

Answer: A
Explanation: Microbial fermentation is widely used in food production for making products like yogurt, bread, and alcoholic beverages.


50. Which of the following processes is used to separate DNA fragments according to their size?

  • A) Centrifugation
  • B) Gel electrophoresis
  • C) PCR
  • D) Cloning

Answer: B
Explanation: Gel electrophoresis is used to separate DNA fragments based on their size by applying an electric field.