1. The first recombinant DNA molecule was constructed in 1972 by Stanley Cohen and Herbert Boyer by linking an antibiotic-resistance gene with a native plasmid of:
Correct Answer: B (Salmonella typhimurium)
Cohen and Boyer isolated an antibiotic-resistance gene by cutting DNA from a plasmid of Salmonella typhimurium and linked it to a plasmid vector to create the first recombinant DNA.
Cohen and Boyer isolated an antibiotic-resistance gene by cutting DNA from a plasmid of Salmonella typhimurium and linked it to a plasmid vector to create the first recombinant DNA.
2. The first restriction endonuclease discovered, which cuts DNA molecules at a specific 6 base-pair recognition sequence, was:
Correct Answer: B (Hind II)
Hind II was the first restriction endonuclease isolated (from Haemophilus influenzae). It always recognizes and cuts DNA at a specific six base-pair sequence.
Hind II was the first restriction endonuclease isolated (from Haemophilus influenzae). It always recognizes and cuts DNA at a specific six base-pair sequence.
3. The restriction enzyme EcoRI recognizes and cleaves DNA at which specific palindromic sequence?
Correct Answer: A (5′-GAATTC-3′ and 3′-CTTAAG-5′)
EcoRI cuts between bases G and A on both strands when the sequence 5′-GAATTC-3′ is present, leaving single-stranded overhanging “sticky ends”.
EcoRI cuts between bases G and A on both strands when the sequence 5′-GAATTC-3′ is present, leaving single-stranded overhanging “sticky ends”.
4. In agarose gel electrophoresis, DNA fragments separate according to their size because:
Correct Answer: B (Negatively charged DNA fragments move towards the anode)
DNA fragments carry a net negative charge due to phosphate groups and migrate toward the positive electrode (anode). The sieving effect of the agarose gel allows smaller fragments to travel farther.
DNA fragments carry a net negative charge due to phosphate groups and migrate toward the positive electrode (anode). The sieving effect of the agarose gel allows smaller fragments to travel farther.
5. Separated DNA bands in an agarose gel can be visualized only after staining with which compound followed by exposure to UV radiation?
Correct Answer: B (Ethidium bromide)
Staining with Ethidium bromide (an intercalating dye) followed by exposure to ultraviolet (UV) light reveals DNA fragments as bright orange colored bands.
Staining with Ethidium bromide (an intercalating dye) followed by exposure to ultraviolet (UV) light reveals DNA fragments as bright orange colored bands.
6. The extraction and cutting out of separated DNA bands from an agarose gel piece is called:
Correct Answer: B (Elution)
Elution is the step where separated DNA bands are cut out from the agarose gel slice and extracted into a clean buffer solution.
Elution is the step where separated DNA bands are cut out from the agarose gel slice and extracted into a clean buffer solution.
7. What is the role of the ‘ori’ (Origin of Replication) sequence in a cloning vector?
Correct Answer: B (Initiates DNA replication and controls copy number)
The origin of replication is a specific sequence where replication starts. Any foreign DNA linked to ‘ori’ replicates within the host, and ‘ori’ dictates the vector’s copy number.
The origin of replication is a specific sequence where replication starts. Any foreign DNA linked to ‘ori’ replicates within the host, and ‘ori’ dictates the vector’s copy number.
8. In the cloning vector pBR322, the ‘rop’ gene codes for:
Correct Answer: B (Proteins involved in the replication of the plasmid)
In pBR322, ‘rop’ stands for Repressor of Primer and codes for proteins involved in regulating plasmid replication and copy number.
In pBR322, ‘rop’ stands for Repressor of Primer and codes for proteins involved in regulating plasmid replication and copy number.
9. If a foreign gene is ligated at the BamHI site in the tetracycline-resistance gene (tetR) of pBR322, the recombinant plasmid will:
Correct Answer: B (Retain ampicillin resistance but lose tetracycline resistance)
Inserting foreign DNA into the BamHI site disrupts the coding sequence of the tetR gene (insertional inactivation), causing the recombinant host to lose tetracycline resistance while remaining ampicillin-resistant.
Inserting foreign DNA into the BamHI site disrupts the coding sequence of the tetR gene (insertional inactivation), causing the recombinant host to lose tetracycline resistance while remaining ampicillin-resistant.
10. In recombinant selection using blue-white screening, recombinant colonies appear white because:
Correct Answer: B (Insertional inactivation of beta-galactosidase gene)
Insertion of rDNA inside the coding sequence of beta-galactosidase inactivates the enzyme, so recombinant colonies cannot produce blue color with X-gal and remain white.
Insertion of rDNA inside the coding sequence of beta-galactosidase inactivates the enzyme, so recombinant colonies cannot produce blue color with X-gal and remain white.
11. Which bacterium is widely utilized as a natural genetic engineer for delivering genes into dicotyledonous plant cells?
Correct Answer: C (Agrobacterium tumefaciens)
The tumor-inducing (Ti) plasmid of Agrobacterium tumefaciens naturally delivers a segment of DNA (T-DNA) into plant genomes. In biotechnology, its disarmed Ti-plasmid acts as a vector.
The tumor-inducing (Ti) plasmid of Agrobacterium tumefaciens naturally delivers a segment of DNA (T-DNA) into plant genomes. In biotechnology, its disarmed Ti-plasmid acts as a vector.
12. To make bacterial cells competent to take up plasmid DNA, they are treated with a specific concentration of a divalent cation such as:
Correct Answer: A (Calcium (Ca2+))
Divalent calcium ions (Ca2+) increase cell membrane permeability by creating transient pores, facilitating DNA uptake when followed by a brief heat shock (42 degrees C).
Divalent calcium ions (Ca2+) increase cell membrane permeability by creating transient pores, facilitating DNA uptake when followed by a brief heat shock (42 degrees C).
13. In the biolistic or gene gun method used for plant transformation, microscopic particles of which metals are coated with DNA and bombarded into target cells?
Correct Answer: B (Gold or Tungsten)
In biolistics (gene gun), high-velocity micro-projectiles of heavy, inert metals like gold or tungsten are coated with DNA and bombarded into plant cells.
In biolistics (gene gun), high-velocity micro-projectiles of heavy, inert metals like gold or tungsten are coated with DNA and bombarded into plant cells.
14. To isolate pure DNA from fungal cells, the cell wall is degraded using which enzyme?
Correct Answer: C (Chitinase)
Bacterial walls are digested with Lysozyme, plant walls with Cellulase, and fungal cell walls (composed of chitin) are digested with Chitinase.
Bacterial walls are digested with Lysozyme, plant walls with Cellulase, and fungal cell walls (composed of chitin) are digested with Chitinase.
15. The precipitation of purified DNA out of an aqueous cellular extract is achieved by adding:
Correct Answer: B (Chilled ethanol)
Adding ice-cold chilled ethanol reduces DNA solubility, causing it to precipitate as fine threads that can be collected by spooling.
Adding ice-cold chilled ethanol reduces DNA solubility, causing it to precipitate as fine threads that can be collected by spooling.
16. What is the correct sequence of steps involved in a single cycle of Polymerase Chain Reaction (PCR)?
Correct Answer: A (Denaturation -> Annealing -> Extension)
PCR proceeds through three temperature steps: Denaturation of double-stranded DNA (~94°C), Annealing of oligonucleotide primers (~50–60°C), and Extension via DNA polymerase (~72°C).
PCR proceeds through three temperature steps: Denaturation of double-stranded DNA (~94°C), Annealing of oligonucleotide primers (~50–60°C), and Extension via DNA polymerase (~72°C).
17. The thermostable DNA polymerase (Taq polymerase) used in PCR is isolated from which thermophilic bacterium?
Correct Answer: C (Thermus aquaticus)
Taq polymerase is extracted from the thermophilic bacterium Thermus aquaticus. It remains stable and active during the high-temperature denaturation phase of PCR.
Taq polymerase is extracted from the thermophilic bacterium Thermus aquaticus. It remains stable and active during the high-temperature denaturation phase of PCR.
18. If a single DNA molecule is amplified through 30 repeated cycles of PCR, the theoretical yield of DNA copies is approximately:
Correct Answer: C (1 billion)
In PCR, DNA amplifies exponentially (2^n). After 30 cycles (2^30), approximately 1.07 billion copies of the target DNA segment are produced.
In PCR, DNA amplifies exponentially (2^n). After 30 cycles (2^30), approximately 1.07 billion copies of the target DNA segment are produced.
19. In a stirred-tank bioreactor, what is the primary function of the sparger?
Correct Answer: B (To bubble sterile air and increase oxygen transfer)
In a sparged stirred-tank bioreactor, sterile air bubbles are introduced via a sparger to increase the surface area available for oxygen diffusion throughout the broth.
In a sparged stirred-tank bioreactor, sterile air bubbles are introduced via a sparger to increase the surface area available for oxygen diffusion throughout the broth.
20. Downstream processing in biotechnology includes which of the following stages?
Correct Answer: C (Separation, purification, and product formulation)
Downstream processing encompasses all post-biosynthetic recovery operations, including product separation, purification, formulation, quality control, and clinical testing.
Downstream processing encompasses all post-biosynthetic recovery operations, including product separation, purification, formulation, quality control, and clinical testing.
21. Why is a cloning vector engineered to contain only a single recognition site for a given restriction enzyme?
Correct Answer: B (Multiple recognition sites generate several fragments)
Having more than one recognition site within a vector generates multiple fragments upon digestion, which fragments the vector and disrupts cloning.
Having more than one recognition site within a vector generates multiple fragments upon digestion, which fragments the vector and disrupts cloning.
22. Microinjection is a technique of direct gene transfer where foreign recombinant DNA is injected directly into:
Correct Answer: B (The nucleus of an animal cell/ovum)
In microinjection, a fine glass micropipette is used to inject recombinant DNA directly into the nucleus of an animal cell.
In microinjection, a fine glass micropipette is used to inject recombinant DNA directly into the nucleus of an animal cell.
23. Which enzyme catalyzes the covalent phosphodiester bonding between the sticky ends of vector DNA and passenger DNA?
Correct Answer: C (DNA Ligase)
DNA ligase seals nicks in double-stranded DNA by forming phosphodiester bonds between adjacent 3′-OH and 5′-phosphate ends.
DNA ligase seals nicks in double-stranded DNA by forming phosphodiester bonds between adjacent 3′-OH and 5′-phosphate ends.
24. Exonucleases differ from endonucleases in that exonucleases:
Correct Answer: A (Remove nucleotides from the terminal ends)
Exonucleases cleave nucleotides one at a time from the ends (5′ or 3′) of DNA strands, whereas endonucleases cut internal phosphodiester bonds at specific sites.
Exonucleases cleave nucleotides one at a time from the ends (5′ or 3′) of DNA strands, whereas endonucleases cut internal phosphodiester bonds at specific sites.
25. The European Federation of Biotechnology (EFB) defines biotechnology as the integration of:
Correct Answer: B (Natural science and organisms, cells, parts thereof, and molecular analogues)
The EFB definition encompasses both traditional views and modern molecular biotechnology into a unified framework.
The EFB definition encompasses both traditional views and modern molecular biotechnology into a unified framework.
26. In Bt cotton, the insecticidal crystal protein (Bt toxin) does not kill the bacterium Bacillus thuringiensis itself because:
Correct Answer: B (The toxin exists as an inactive protoxin)
The Bt toxin is synthesized as an inactive crystalline protoxin. Once ingested by an insect, the alkaline pH of the insect midgut solubilizes the crystals and converts them into the active toxin.
The Bt toxin is synthesized as an inactive crystalline protoxin. Once ingested by an insect, the alkaline pH of the insect midgut solubilizes the crystals and converts them into the active toxin.
27. The activated Bt toxin causes death of susceptible insects by:
Correct Answer: B (Binding to midgut epithelial cells and creating pores)
Active Bt toxin binds to surface receptors on midgut epithelial cells, forming pores that lead to cell lysis, gut perforation, and insect death.
Active Bt toxin binds to surface receptors on midgut epithelial cells, forming pores that lead to cell lysis, gut perforation, and insect death.
28. Which specific Bt genes code for toxins that control cotton bollworms?
Correct Answer: A (cryIAc and cryIIAb)
According to NCERT, proteins encoded by cryIAc and cryIIAb control cotton bollworms, while cryIAb controls the corn borer.
According to NCERT, proteins encoded by cryIAc and cryIIAb control cotton bollworms, while cryIAb controls the corn borer.
29. The gene cryIAb is specifically introduced into crops to protect against:
Correct Answer: B (Corn borer)
The cryIAb endotoxin gene specifically targets and controls corn borer infestations in transgenic maize/corn plants.
The cryIAb endotoxin gene specifically targets and controls corn borer infestations in transgenic maize/corn plants.
30. RNA interference (RNAi) protects tobacco roots against the nematode Meloidogyne incognita by:
Correct Answer: B (Silencing specific nematode mRNA using dsRNA)
RNAi silences target mRNA via complementary double-stranded RNA (dsRNA), preventing the synthesis of essential proteins and stopping parasite survival.
RNAi silences target mRNA via complementary double-stranded RNA (dsRNA), preventing the synthesis of essential proteins and stopping parasite survival.
31. Which vector was used to introduce nematode-specific genes producing both sense and anti-sense RNA into tobacco host plants?
Correct Answer: C (Agrobacterium tumefaciens)
Agrobacterium vectors introduce nematode-specific DNA into host plant genomes such that both sense and antisense strands are transcribed, producing regulatory dsRNA.
Agrobacterium vectors introduce nematode-specific DNA into host plant genomes such that both sense and antisense strands are transcribed, producing regulatory dsRNA.
32. How does proinsulin synthesized in humans differ from mature, functionally active insulin?
Correct Answer: B (Proinsulin contains an extra C-peptide)
Proinsulin contains A, B, and connecting C chains. During post-translational proteolytic cleavage, the C-peptide is removed to yield mature insulin (A and B chains linked by disulfide bridges).
Proinsulin contains A, B, and connecting C chains. During post-translational proteolytic cleavage, the C-peptide is removed to yield mature insulin (A and B chains linked by disulfide bridges).
33. In 1983, the American company Eli Lilly produced human insulin (Humulin) by:
Correct Answer: B (Synthesizing chains A and B separately in E. coli)
Eli Lilly synthesized two DNA sequences corresponding to insulin A and B chains, expressed them separately in E. coli, extracted them, and joined them with disulfide bonds.
Eli Lilly synthesized two DNA sequences corresponding to insulin A and B chains, expressed them separately in E. coli, extracted them, and joined them with disulfide bonds.
34. The first clinical gene therapy was administered in 1990 to a 4-year-old girl suffering from:
Correct Answer: B (Adenosine Deaminase (ADA) deficiency)
ADA deficiency causes severe combined immunodeficiency (SCID). In 1990, functional ADA cDNA was introduced into the patient’s cultured T-lymphocytes using a retroviral vector.
ADA deficiency causes severe combined immunodeficiency (SCID). In 1990, functional ADA cDNA was introduced into the patient’s cultured T-lymphocytes using a retroviral vector.
35. Why do lymphocyte infusions for ADA deficiency require periodic replacement?
Correct Answer: B (Transfused lymphocytes are not immortal)
Genetically engineered lymphocytes have a limited lifespan and eventually die, requiring repeat transfusions unless stem cells are transformed at an early embryonic stage.
Genetically engineered lymphocytes have a limited lifespan and eventually die, requiring repeat transfusions unless stem cells are transformed at an early embryonic stage.
36. A permanent cure for Adenosine Deaminase (ADA) deficiency can be achieved if:
Correct Answer: B (Gene introduced into cells at early embryonic stages)
Introducing the functional ADA gene into bone marrow stem cells during early embryonic development provides a permanent cure because all descendant cell lines inherit the gene.
Introducing the functional ADA gene into bone marrow stem cells during early embryonic development provides a permanent cure because all descendant cell lines inherit the gene.
37. In molecular diagnostics, single-stranded DNA or RNA tagged with a radioactive molecule used to detect complementary genetic sequences is called a:
Correct Answer: C (Probe)
A probe is a single-stranded nucleic acid sequence labeled with a radioactive isotope or fluorophore that hybridizes with complementary target DNA for autoradiographic detection.
A probe is a single-stranded nucleic acid sequence labeled with a radioactive isotope or fluorophore that hybridizes with complementary target DNA for autoradiographic detection.
38. In autoradiography, a mutated gene fails to appear on a photographic film because:
Correct Answer: B (Probe lacks base complementarity with mutated gene)
Probes are designed complementary to the wild-type gene. Any mutation creates a mismatch, preventing hybridization and photographic exposure.
Probes are designed complementary to the wild-type gene. Any mutation creates a mismatch, preventing hybridization and photographic exposure.
39. The Enzyme-Linked Immunosorbent Assay (ELISA) technique operates on the fundamental principle of:
Correct Answer: B (Antigen-Antibody interaction)
ELISA detects infections either by identifying pathogen-specific antigens (proteins/glycoproteins) or by quantifying host-generated antibodies.
ELISA detects infections either by identifying pathogen-specific antigens (proteins/glycoproteins) or by quantifying host-generated antibodies.
40. Over 95 percent of all existing transgenic laboratory animals used in research are:
Correct Answer: C (Mice)
Transgenic mice account for more than 95% of all transgenic animal models used in biomedical research, disease modeling, and safety testing.
Transgenic mice account for more than 95% of all transgenic animal models used in biomedical research, disease modeling, and safety testing.
41. The first transgenic cow, ‘Rosie’ (produced in 1997), produced human protein-enriched milk containing 2.4 grams per liter of:
Correct Answer: B (Human alpha-lactalbumin)
Rosie’s milk contained human alpha-lactalbumin, making it nutritionally more balanced for human babies than natural bovine milk.
Rosie’s milk contained human alpha-lactalbumin, making it nutritionally more balanced for human babies than natural bovine milk.
42. Transgenic animals engineered to produce the human protein alpha-1-antitrypsin are used in the medical treatment of:
Correct Answer: C (Emphysema)
Human alpha-1-antitrypsin is a protease inhibitor synthesized via transgenic animal bioreactors to manage emphysema-induced lung tissue degradation.
Human alpha-1-antitrypsin is a protease inhibitor synthesized via transgenic animal bioreactors to manage emphysema-induced lung tissue degradation.
43. Before being administered in human clinical trials, batches of the polio vaccine are rigorously tested for batch safety on:
Correct Answer: C (Transgenic mice)
Transgenic mice expressing human poliovirus receptors are used to evaluate polio vaccine safety and potency before releasing batches for human use.
Transgenic mice expressing human poliovirus receptors are used to evaluate polio vaccine safety and potency before releasing batches for human use.
44. “Golden Rice” is a genetically modified biofortified crop developed to combat dietary deficiencies of:
Correct Answer: B (Vitamin A)
Golden Rice (Oryza sativa) is engineered with daffodil and bacterial genes to synthesize beta-carotene (provitamin A) in its endosperm, addressing childhood blindness.
Golden Rice (Oryza sativa) is engineered with daffodil and bacterial genes to synthesize beta-carotene (provitamin A) in its endosperm, addressing childhood blindness.
45. In India, which statutory body under the Ministry of Environment evaluates the safety and validity of GM research and commercial releases?
Correct Answer: B (GEAC)
The Genetic Engineering Appraisal Committee (GEAC) regulates environmental clearances, biosafety guidelines, and commercial release protocols for genetically modified organisms.
The Genetic Engineering Appraisal Committee (GEAC) regulates environmental clearances, biosafety guidelines, and commercial release protocols for genetically modified organisms.
46. In 1997, an American company was granted a patent on Basmati rice by the US Patent and Trademark Office through cross-breeding with:
Correct Answer: B (Semi-dwarf varieties)
The company crossed Indian Basmati with semi-dwarf varieties and claimed it as an original novel invention, leading to international biopiracy disputes.
The company crossed Indian Basmati with semi-dwarf varieties and claimed it as an original novel invention, leading to international biopiracy disputes.
47. Approximately how many documented distinct varieties of traditional Basmati rice are grown in India?
Correct Answer: B (27 documented varieties)
India has 200,000 varieties of rice; of these, 27 documented varieties are traditional aromatic Basmati strains.
India has 200,000 varieties of rice; of these, 27 documented varieties are traditional aromatic Basmati strains.
48. Biopiracy refers to:
Correct Answer: B (Unauthorized commercial exploitation of bioresources)
Biopiracy involves multinational corporations or organizations patenting biological resources and traditional knowledge of indigenous nations without authorization or benefit-sharing.
Biopiracy involves multinational corporations or organizations patenting biological resources and traditional knowledge of indigenous nations without authorization or benefit-sharing.
49. The ‘Flavr Savr’ transgenic tomato was developed to have an extended shelf-life by using antisense RNA technology against the enzyme:
Correct Answer: A (Polygalacturonase)
Antisense RNA inhibits polygalacturonase (which degrades cell-wall pectin during fruit ripening), delaying softening and prolonging shelf life.
Antisense RNA inhibits polygalacturonase (which degrades cell-wall pectin during fruit ripening), delaying softening and prolonging shelf life.
50. The Indian Parliament cleared the second amendment of the Indian Patents Bill to specifically address:
Correct Answer: B (Patent terms, emergency provisions, and R&D initiatives)
The amendment protects national biological wealth against biopiracy while modernizing patent terms, emergency provisions, and research incentives.
The amendment protects national biological wealth against biopiracy while modernizing patent terms, emergency provisions, and research incentives.