GENERAL MICROBIOLOGY- PAGE 1
GENERAL MICROBIOLOGY- PAGE 1 MCQs
1. A feature that accounts for resolution in microscopes is
(A) condenser (B) wavelength of light (C) intensity of light (D) illumination source
Ans: B
2. A mixed culture is
(A) one that contains two or more known species (B) one that has been adequately stirred
(C) the same as a contaminated culture (D) a natural water sample containing bacteria, algae and protozoa
Ans: A
3. Gram staining differentiates cells on the basis of
(A) Cell wall composition (B) Cell membrane structure (C) Cell inclusion bodies (D) Cell shape
Ans: A
4. Most fungi derive nutrition through
(A) digesting organic substrates (B) engulfing bacteria (C) photosynthesis (D) engulfing protozoa
Ans: A
5. Prions are made of
(A) DNA and protein (B) RNA and protein (C) only protein (D) only RNA
Ans: C
6. Viral genome is covered in a protein coat made up of
(A) spikes (B) virions (C) capsomeres (D) envelope
Ans: C
7. Oxygen is toxic for obligate anaerobes because they lack
(A) superoxide dismutase (B) TCA cycle (C) glycolysis (D) electron transport chain
Ans: A
8. Active transport of a substance across a membrane requires
(A) a high concentration of substance outside (B) ATP (C) high osmotic pressure (D) ability of substance to diffuse across the membrane
Ans: B
9. Chemolithotrophs utilize ____ as energy source
(A) reduced inorganic compounds such as sulphide, ammonia (B) oxidized inorganic compounds such as nitrate, sulfate
(C) Carbondioxide (D) organic compounds
Ans: A
10. Denitrifiers can help mitigate green house emission by reducing the levels of
(A) Ammonia (B) nitrous oxide (C) Nitrates (D) Methane
Ans: B
11. The enzyme phosphofructokinase belongs to the class
(A) Lyase (B) Isomerase (C) Transferase (D) Hydrolase
Ans: C
12. In the genetic code, one amino acid may be coded by more than one triplet code. This is referred to as
(A) Wobble hypothesis (B) Degeneracy of the code
(C) Universality of the code (D) Non-overlapping nature of the code
Ans: B
13. A technique in which a short fluorescently labelled nucleic acid probe binds to the complementary DNA in the microbial cell and allows the microscopic detection of fluorescent cells is
(A) Autoradiography (B) FISH (C) Stable isotope probing (D) CHIP assay
Ans: B
14. Which of the following is true about metagenomics?
(A) It is the same as whole genome sequencing
(B) It is the analysis of genomes of the entire community
(C) It requires isolation and cultivation of diverse organisms from a sample
(D) It gives only phylogenetic information but not functional information
Ans: B
15. The first bacterial genome that was sequenced was of
(A) Escherichia coli (B) Bacillus subtilis (C) Haemophilus influenzae (D) Mycoplasma genitalium
Ans: C
16. BLAST is
(A) A local alignment tool (B) A multiple alignment tool
(C) A database of similar sequences (D) A phylogenetic clustering tool
Ans: A
17. Quorum sensing in bacteria is mediated by signalling molecules known as
(A) Secondary messengers (B) Autoinducers (C) Pheromones (D) Elicitors
Ans: B
18. In Bacillus subtilis differential gene expression during sporulation is controlled by
(A) ppGpp (B) cAMP (C) alternative sigma factors (D) MAP kinase signalling
Ans: C
19. Individuals belonging to the same species present and in the same geographical location form a
(A) Family (B) Population (C) Guild (D) Community
Ans: B
20. Which of the following is considered secondary structure of proteins?
(A) Alpha helix (B) Peptide sequence (C) Subunit arrangement (D) Covalent modification
Ans: A
21. Increasing specificity of PCR can be done by
(A) Increasing annealing temperature (B) Decreasing annealing temperature
(C) Increasing elongation temperature (D) Decreasing elongation temperature
Ans: A
22. Which of the following fuels CANNOT be produced by microorganisms in the lab?
(A) Hydrogen (B) Methane (C) Ethanol (D) Crude oil
Ans: D
23. After conjugation with an Hfr strain, the F minus
(A) becomes F plus (B) becomes Hfr (C) becomes F prime (D) remains F minus
Ans: D
24. Antibiotics that affect prokaryotic translation when used to treat humans have side effects because
(A) They also kill normal flora (B) They affect digestion of proteins
(C) They affect 70S ribosomal machinery of human cell organelles (D) They cause breakdown of muscle protein
Ans: C
25. Interaction between two organisms in which one is harmed but the other is NOT benefitted is known as
(A) Amensalism (B) Commensalism (C) Syntrophism (D) Parasitism
Ans: A
26. The human microbiome is correctly defined as
(A) Microorganisms found in human faeces (B) Microorganisms residing on human surface (skin)
(C) All microorganisms found on any part of the human body (D) Bacteria and Archea found in the human intestine
Ans: C
27. A compost pile would most likely harbor
(A) Alkaliphiles (B) Halophiles (C) Acidophiles (D) Thermophiles
Ans: D
28. Nod factors are produced by
(A) Leguminous plants in response to signals from Nodule forming bacteria
(B) Nodule forming bacteria in response to signals from leguminous plants
(C) Constitutively by leguminous plants
(D) Constitutively by nodule forming bacteria
Ans: B
29. Filamentous bacteria that fix nitrogen in symbiotic association with plants are
(A) Mycorrhiza (B) Frankia (C) Azolla (D) Rhizobia
Ans: B
30. Methanotrophs
(A) produce methane (B) belong to archaebacteria
(C) use methane as carbon and energy source (D) assimilate methylated compounds
Ans: C
31. The Irish potato famine in the 1840s was caused by the pathogen
(A) Ustilago maydis (B) Phytopthera infestans (C) Alternaria solani (D) Ralstonia solanacearum
Ans: B
32. Systemic acquired resistance is a type of plant defense response that
(A) Is localised around site of pathogen attack (B) Is long lasting throughout the plant
(C) Involves production of reactive oxygen species (D) Is specific against the pathogen
Ans: B
33. Ames test detects mutagens on the basis of their effect on
(A) live bacteria (B) bacterial extracts (C) liver cells (D) liver extracts
Ans: A
34. Which one of the following is a primary lymphoid organ:
(A) Lymph nodes (B) Spleen (C) Thyroid (D) Thymus
Ans: D
35. Professional antigen presenting cells include all except
(A) Macrophages (B) Dendritic cells (C) B lymphocytes (D) Neutrophils
Ans: D
36. Which of the following is a neurotoxin?
(A) Diphtheria toxin (B) Cholera toxin (C) Botulinum toxin (D) Shiga toxin
Ans: C
37. Genetically modified cotton in India has been engineered for
(A) Higher yield (B) Drought resistance (C) Insect resistance (D) Salt resistance
Ans: C
38. A bioreactor/fermenter designed for adequate supply of oxygen without agitation is
(A) Stirred tank bioreactors (B) Air-lift fermenter (C) Packed bed reactor (D) Photo bioreactor
Ans: B
39. Quantity of DNA in a sample can be measured by absorbance at
(A) 280 nm (B) 260 nm (C) 230 nm (D) 240 nm
Ans: B
40. According to the endosymbiotic theory, mitochondria have evolved from
(A) Proteobacteria (B) Actinobacteria (C) Firmicutes (D) Cyanobacteria
Ans: A
41. Among the three domains of life, the two which are more related are
(A) Eubacteria and Archaebacteria (B) Eubacteria and Eukaryotes
(C) Archaebacteria and Eukaryotes (D) All three are equally related
Ans: C
42. Stromatolites are
(A) Structures made up of minerals hanging from cave roofs (B) A type of sedimentary rocks with fossilized bacteria
(C) A type of coral (D) A type siliceous sponge
Ans: B
43. V3-V4 sequencing for identification of bacteria involves
(A) rRNA (B) tRNA (C) snRNA (D) microRNA
Ans: A
44. R plasmids encode genes for
(A) Colicins (B) Antibiotic resistance (C) Hydrocarbon degradation (D) Nitrogen fixation
Ans: B
45. HEPA filters are related to
(A) Water purification systems (B) Biological safety hoods (C) Sewage treatment plants (D) Industrial bioreactors
Ans: B
46. A bacteriophage that has single stranded DNA is
(A) Lambda (B) T4 (C) phiX174 (D) Mu
Ans: C
47. Beta-mercaptoethanol breaks which bonds in proteins?
(A) Peptide bonds (B) Disulphide linkages (C) Hydrogen bond (D) Ionic interactions
Ans: B
48. A common property of proteins that have helix-turn-helix motif, zinc finger domain and leucine zipper domain is that they are
(A) Transcriptional activators (B) Receptor molecules
(C) DNA binding proteins (D) Repressor molecules
Ans: C
49. RNAi is associated with
(A) RNA insertion (B) Gene silencing (C) Gene editing (D) Removal of introns from pre-mRNA
Ans: B
50. A mutagen that causes insertion of a single base in a nucleotide sequence would lead to
(A) Mismatch errors (B) Transition mutations (C) Transversion mutations (D) Frameshift mutations
Ans: D
(A) condenser (B) wavelength of light (C) intensity of light (D) illumination source
Ans: B
2. A mixed culture is
(A) one that contains two or more known species (B) one that has been adequately stirred
(C) the same as a contaminated culture (D) a natural water sample containing bacteria, algae and protozoa
Ans: A
3. Gram staining differentiates cells on the basis of
(A) Cell wall composition (B) Cell membrane structure (C) Cell inclusion bodies (D) Cell shape
Ans: A
4. Most fungi derive nutrition through
(A) digesting organic substrates (B) engulfing bacteria (C) photosynthesis (D) engulfing protozoa
Ans: A
5. Prions are made of
(A) DNA and protein (B) RNA and protein (C) only protein (D) only RNA
Ans: C
6. Viral genome is covered in a protein coat made up of
(A) spikes (B) virions (C) capsomeres (D) envelope
Ans: C
7. Oxygen is toxic for obligate anaerobes because they lack
(A) superoxide dismutase (B) TCA cycle (C) glycolysis (D) electron transport chain
Ans: A
8. Active transport of a substance across a membrane requires
(A) a high concentration of substance outside (B) ATP (C) high osmotic pressure (D) ability of substance to diffuse across the membrane
Ans: B
9. Chemolithotrophs utilize ____ as energy source
(A) reduced inorganic compounds such as sulphide, ammonia (B) oxidized inorganic compounds such as nitrate, sulfate
(C) Carbondioxide (D) organic compounds
Ans: A
10. Denitrifiers can help mitigate green house emission by reducing the levels of
(A) Ammonia (B) nitrous oxide (C) Nitrates (D) Methane
Ans: B
11. The enzyme phosphofructokinase belongs to the class
(A) Lyase (B) Isomerase (C) Transferase (D) Hydrolase
Ans: C
12. In the genetic code, one amino acid may be coded by more than one triplet code. This is referred to as
(A) Wobble hypothesis (B) Degeneracy of the code
(C) Universality of the code (D) Non-overlapping nature of the code
Ans: B
13. A technique in which a short fluorescently labelled nucleic acid probe binds to the complementary DNA in the microbial cell and allows the microscopic detection of fluorescent cells is
(A) Autoradiography (B) FISH (C) Stable isotope probing (D) CHIP assay
Ans: B
14. Which of the following is true about metagenomics?
(A) It is the same as whole genome sequencing
(B) It is the analysis of genomes of the entire community
(C) It requires isolation and cultivation of diverse organisms from a sample
(D) It gives only phylogenetic information but not functional information
Ans: B
15. The first bacterial genome that was sequenced was of
(A) Escherichia coli (B) Bacillus subtilis (C) Haemophilus influenzae (D) Mycoplasma genitalium
Ans: C
16. BLAST is
(A) A local alignment tool (B) A multiple alignment tool
(C) A database of similar sequences (D) A phylogenetic clustering tool
Ans: A
17. Quorum sensing in bacteria is mediated by signalling molecules known as
(A) Secondary messengers (B) Autoinducers (C) Pheromones (D) Elicitors
Ans: B
18. In Bacillus subtilis differential gene expression during sporulation is controlled by
(A) ppGpp (B) cAMP (C) alternative sigma factors (D) MAP kinase signalling
Ans: C
19. Individuals belonging to the same species present and in the same geographical location form a
(A) Family (B) Population (C) Guild (D) Community
Ans: B
20. Which of the following is considered secondary structure of proteins?
(A) Alpha helix (B) Peptide sequence (C) Subunit arrangement (D) Covalent modification
Ans: A
21. Increasing specificity of PCR can be done by
(A) Increasing annealing temperature (B) Decreasing annealing temperature
(C) Increasing elongation temperature (D) Decreasing elongation temperature
Ans: A
22. Which of the following fuels CANNOT be produced by microorganisms in the lab?
(A) Hydrogen (B) Methane (C) Ethanol (D) Crude oil
Ans: D
23. After conjugation with an Hfr strain, the F minus
(A) becomes F plus (B) becomes Hfr (C) becomes F prime (D) remains F minus
Ans: D
24. Antibiotics that affect prokaryotic translation when used to treat humans have side effects because
(A) They also kill normal flora (B) They affect digestion of proteins
(C) They affect 70S ribosomal machinery of human cell organelles (D) They cause breakdown of muscle protein
Ans: C
25. Interaction between two organisms in which one is harmed but the other is NOT benefitted is known as
(A) Amensalism (B) Commensalism (C) Syntrophism (D) Parasitism
Ans: A
26. The human microbiome is correctly defined as
(A) Microorganisms found in human faeces (B) Microorganisms residing on human surface (skin)
(C) All microorganisms found on any part of the human body (D) Bacteria and Archea found in the human intestine
Ans: C
27. A compost pile would most likely harbor
(A) Alkaliphiles (B) Halophiles (C) Acidophiles (D) Thermophiles
Ans: D
28. Nod factors are produced by
(A) Leguminous plants in response to signals from Nodule forming bacteria
(B) Nodule forming bacteria in response to signals from leguminous plants
(C) Constitutively by leguminous plants
(D) Constitutively by nodule forming bacteria
Ans: B
29. Filamentous bacteria that fix nitrogen in symbiotic association with plants are
(A) Mycorrhiza (B) Frankia (C) Azolla (D) Rhizobia
Ans: B
30. Methanotrophs
(A) produce methane (B) belong to archaebacteria
(C) use methane as carbon and energy source (D) assimilate methylated compounds
Ans: C
31. The Irish potato famine in the 1840s was caused by the pathogen
(A) Ustilago maydis (B) Phytopthera infestans (C) Alternaria solani (D) Ralstonia solanacearum
Ans: B
32. Systemic acquired resistance is a type of plant defense response that
(A) Is localised around site of pathogen attack (B) Is long lasting throughout the plant
(C) Involves production of reactive oxygen species (D) Is specific against the pathogen
Ans: B
33. Ames test detects mutagens on the basis of their effect on
(A) live bacteria (B) bacterial extracts (C) liver cells (D) liver extracts
Ans: A
34. Which one of the following is a primary lymphoid organ:
(A) Lymph nodes (B) Spleen (C) Thyroid (D) Thymus
Ans: D
35. Professional antigen presenting cells include all except
(A) Macrophages (B) Dendritic cells (C) B lymphocytes (D) Neutrophils
Ans: D
36. Which of the following is a neurotoxin?
(A) Diphtheria toxin (B) Cholera toxin (C) Botulinum toxin (D) Shiga toxin
Ans: C
37. Genetically modified cotton in India has been engineered for
(A) Higher yield (B) Drought resistance (C) Insect resistance (D) Salt resistance
Ans: C
38. A bioreactor/fermenter designed for adequate supply of oxygen without agitation is
(A) Stirred tank bioreactors (B) Air-lift fermenter (C) Packed bed reactor (D) Photo bioreactor
Ans: B
39. Quantity of DNA in a sample can be measured by absorbance at
(A) 280 nm (B) 260 nm (C) 230 nm (D) 240 nm
Ans: B
40. According to the endosymbiotic theory, mitochondria have evolved from
(A) Proteobacteria (B) Actinobacteria (C) Firmicutes (D) Cyanobacteria
Ans: A
41. Among the three domains of life, the two which are more related are
(A) Eubacteria and Archaebacteria (B) Eubacteria and Eukaryotes
(C) Archaebacteria and Eukaryotes (D) All three are equally related
Ans: C
42. Stromatolites are
(A) Structures made up of minerals hanging from cave roofs (B) A type of sedimentary rocks with fossilized bacteria
(C) A type of coral (D) A type siliceous sponge
Ans: B
43. V3-V4 sequencing for identification of bacteria involves
(A) rRNA (B) tRNA (C) snRNA (D) microRNA
Ans: A
44. R plasmids encode genes for
(A) Colicins (B) Antibiotic resistance (C) Hydrocarbon degradation (D) Nitrogen fixation
Ans: B
45. HEPA filters are related to
(A) Water purification systems (B) Biological safety hoods (C) Sewage treatment plants (D) Industrial bioreactors
Ans: B
46. A bacteriophage that has single stranded DNA is
(A) Lambda (B) T4 (C) phiX174 (D) Mu
Ans: C
47. Beta-mercaptoethanol breaks which bonds in proteins?
(A) Peptide bonds (B) Disulphide linkages (C) Hydrogen bond (D) Ionic interactions
Ans: B
48. A common property of proteins that have helix-turn-helix motif, zinc finger domain and leucine zipper domain is that they are
(A) Transcriptional activators (B) Receptor molecules
(C) DNA binding proteins (D) Repressor molecules
Ans: C
49. RNAi is associated with
(A) RNA insertion (B) Gene silencing (C) Gene editing (D) Removal of introns from pre-mRNA
Ans: B
50. A mutagen that causes insertion of a single base in a nucleotide sequence would lead to
(A) Mismatch errors (B) Transition mutations (C) Transversion mutations (D) Frameshift mutations
Ans: D
51. The biological definition of species was proposed by
(A) Charles Darwin (B) Jean-Baptiste Lamarck (C) Theodosius Dobzhansky (D) Ernst Mayr
Ans: D
52. Which of the following compound has defined molecular weight?
(A) Starch (B) Xylan (C) Insulin (D) Inulin
Ans: C
53. Teichoic acid is a part of the cell wall of which of the following bacteria?
(A) Escherichia coli (B) Streptococcus lactis (C) Shigella sonnei (D) Salmonella typhi
Ans: B
54. A treatment that does not kill endospores is
(A) autoclaving (B) paseurization (C) hot-air sterilization (D) incineration
Ans: B
55. The Open reading Frame (ORF) refers to
(A) any fragment of DNA (B) a fragment of DNA with stop codon
(C) a fragment of DNA with start codon (D) a fragment of DNA with start and stop codons
Ans: D
56. A sequence that can be located at large distances away from the promoter but still causes transcriptional activation is known as
(A) Insulator (B) Enhancer (C) Silencer (D) Activator
Ans: B
57. Bergey’s Manual of Systematic Bacteriology differs from Bergey’s Manual of Determinative Bacteriology in that the former
(A) groups bacteria according to phenotypic differences (B) groups bacteria according to phylogenetic relationships
(C) groups bacteria according to pathogenic properties (D) groups bacteria according to environmental habitat
Ans: B
58. Illumina Hi Seq is a type of
(A) Microscope (B) Advanced illumination system (C) Next generation sequencing Machine (D) Gel documentation system
Ans: C
59. Agar agar is produced from
(A) green algae (B) red algae (C) brown algae (D) blue green algae
Ans: B
60. Conidiospores are produced in
(A) Mucor (B) Absidia (C) Phytophthora (D) Neurospora
Ans: D
61. Ribozyme was first discovered in
(A) Entamoeba histolytica (B) Plasmodium falcifarum
(C) Tetrahymena thermophila (D) Leishmania major
Ans: C
62. Saccharomyces cerevisiae grows by
(A) binary fission (B) budding (C) hyphal growth (D) hyphal growth followed by fragmentation
Ans: B
63. An encapsulated bacterium can be virulent because the capsule
(A) resists phagocytosis (B) is an endotoxins (C) destroys host tissue (D) is an exotoxin
Ans: A
64. Helicobacter pylori uses urease to counteract a chemical defense in the human organ in which it lives. This chemical defense is against (A) lysozyme (B) hydrochloric acid (C) superoxide radicals (D) sebum
Ans: B
65. Worldwide, the primary method for transmitting HIV is
(A) homosexual sex (B) heterosexual sex (C) use of injecting drugs (D) blood transfusions
Ans: B
66. Bacteria without cell wall belong to
(A) Mycoplasma (B) Rickettsia (C) Bacteroidetes (D) Halophiles
Ans: A
67. The enzyme useful in the conversion of penicillin G to 6-aminopenicillanic acid (6-APA)
(A) penicillin acylase (B) penicillinase (C) carboxypeptidase (D) aminopeptidase
Ans: A
68. When E.coli is grown in the presence of both Glucose and Lactose, glucose is first metabolised followed by lactose. This is referred to as (A) Positive induction (B) Catabolite repression (C) Cometabolism (D) Constitutive gene expression
Ans: B
69. Endotoxin is responsible for symptoms caused by
(A) Neisseria meningitidis (B) Streptococcus pyogenes
(C) Listeria monocytogenes (D) Clostridium tetani
Ans: A
70. A patient with nausea, vomiting and diarrhea within 5 hours after eating most likely has
(A) shigellosis (B) cholera
(C) E. coli gastroenteritis (D) staphylococcal food poisoning
Ans: D
71. A technique based on sedimentation is
(A) Electrophoresis (B) Centrifugation (C) Chromatography (D) Spectrophometry
Ans: B
72. Which is a correct match between the PCR step and the temperature used?
(A) Annealing : 94-96 degree C (B) Denaturation : 60-65 degree C (C) Extension : 70-72 degree C (D) Hold : 37 degree C
Ans: C
73. A technique for detecting chromosome number abnormalities in cancer is
(A) Pedigree analysis (B) Karyotyping (C) PCR (D) ELISA
Ans: B
74. MALDI TOF is useful for
(A) DNA fingerprinting (B) Peptide fingerprinting (C) Studying protein DNA interactions (D) Analysis of DNA methylation
Ans: B
75. Two bacteria show DNA:DNA hybridization of 75% . It may be concluded that
(A) They are same strains (B) They are same species
(C) They are same genus but different species (D) They are neither same genus nor same species
Ans: B
76. Which of the following trace element is particularly essential for nitrogen fixation?
(A) Nickel (B) Molybdenum (C) Zinc (D) Copper
Ans: B
77. Which of the following techniques DOES NOT involve PCR?
(A) ARISA (B) T-RFLP (C) FAME (D) DGGE
Ans: C
78. Which of the following is mycorrhizal biofertilizer?
(A) Nostoc (B) Anabaena (C) Glomus (D) Rhizobium
Ans: C
79. “Avirulence” genes are
(A) Present in the plant pathogen and cause disease in plants (B) Present in the plant pathogen and cause defense induction in plants
(C) Present in the plant and cause resistance to pathogen attack (D) Present in the plant and make them susceptible to pathogen attack
Ans: B
80. Which is an INCORRECT match between the scientist and their contribution I the field of Microbiology?
(A) Robert Hooke : discovery of causative agents for TB and anthrax (B) Joseph Lister : Antiseptic methods during surgery (C) Antoni van Leeuwenhoek : discovery of bacteria (D) Martinus Beijerinck : Discovery of Nitrogen fixation
Ans: A
81. The fluorescence dye DAPI can stain cells because it binds to
(A) Cell wall (B) Proteins (C) DNA (D) Cell membrane
Ans: C
82. A Nobel Laureate who received the prize for discovery of prions is
(A) David Baltimore (B) Stanley Prusiner (C) Harold Varmus (D) Barry Marshall
Ans: B
83. A process by which introduction of excess mineral nutrients in a water body leads to dense growth of plants and algae leading to environmental deterioration is
(A) Biomagnification (B) Eutrophication (C) Bioaccumulation (D) Bioconcentration
Ans: B
84. Which group of microorganisms was responsible for generation of molecular oxygen in the primitive Earth atmosphere?
(A) Proteobacteria (B) Cyanobacteria (C) Actinomycetes (D) Methanogens
Ans: B
85. Confocal Microscopy involves
(A) Laser beams (B) Fluorescence dyes (C) Live specimens (D) All of the above
Ans: D
86. Which is an example of a retrovirus?
(A) Herpesvirus (B) HIV (C) Influenza virus (D) Polio virus
Ans: B
87. CRISPR sequences are
(A) Located on the bacterial genome (B) Present in viral genome
(C) Encode various functional proteins that help viral replication (D) Derived by lateral transfer
Ans: A
88. The common feature of CRISPR-Cas9 and TALENS is that
(A) They originate from viruses (B) They act through guide RNA
(C) They can be used for genome editing (D) All of the above
Ans: C
89. What is the earliest step in the entry of HIV into the target human cell?
(A) Fusion of envelope with cell membrane (B) Binding of env protein to CD4 receptor
(C) Phagocytosis of the viral particle (D) Binding of coreceptor with env protein
Ans: B
90. RNA-dependent RNA polymerase is found in
(A) Double stranded DNA viruses
(B) Single stranded DNA viruses (C) RNA viruses (D) Retroviruses
Ans: C
91. A cluster of genes under a common promoter is known as
(A) Regulon (B) Operator (C) Transposon (D) Operon
Ans: D
92. Mutations in lac repressor can lead to
(A) Constitutive expression (B) Uninducible phenotype (C) Super repressor (D) Any of the above
Ans: D
93. IPTG is a gratuitous inducer. This means
(A) It is artificial and not natural (B) It is transported freely across the membrane
(C) It causes induction but does not get metabolized (D) It was discovered by chance
Ans: C
(A) Charles Darwin (B) Jean-Baptiste Lamarck (C) Theodosius Dobzhansky (D) Ernst Mayr
Ans: D
52. Which of the following compound has defined molecular weight?
(A) Starch (B) Xylan (C) Insulin (D) Inulin
Ans: C
53. Teichoic acid is a part of the cell wall of which of the following bacteria?
(A) Escherichia coli (B) Streptococcus lactis (C) Shigella sonnei (D) Salmonella typhi
Ans: B
54. A treatment that does not kill endospores is
(A) autoclaving (B) paseurization (C) hot-air sterilization (D) incineration
Ans: B
55. The Open reading Frame (ORF) refers to
(A) any fragment of DNA (B) a fragment of DNA with stop codon
(C) a fragment of DNA with start codon (D) a fragment of DNA with start and stop codons
Ans: D
56. A sequence that can be located at large distances away from the promoter but still causes transcriptional activation is known as
(A) Insulator (B) Enhancer (C) Silencer (D) Activator
Ans: B
57. Bergey’s Manual of Systematic Bacteriology differs from Bergey’s Manual of Determinative Bacteriology in that the former
(A) groups bacteria according to phenotypic differences (B) groups bacteria according to phylogenetic relationships
(C) groups bacteria according to pathogenic properties (D) groups bacteria according to environmental habitat
Ans: B
58. Illumina Hi Seq is a type of
(A) Microscope (B) Advanced illumination system (C) Next generation sequencing Machine (D) Gel documentation system
Ans: C
59. Agar agar is produced from
(A) green algae (B) red algae (C) brown algae (D) blue green algae
Ans: B
60. Conidiospores are produced in
(A) Mucor (B) Absidia (C) Phytophthora (D) Neurospora
Ans: D
61. Ribozyme was first discovered in
(A) Entamoeba histolytica (B) Plasmodium falcifarum
(C) Tetrahymena thermophila (D) Leishmania major
Ans: C
62. Saccharomyces cerevisiae grows by
(A) binary fission (B) budding (C) hyphal growth (D) hyphal growth followed by fragmentation
Ans: B
63. An encapsulated bacterium can be virulent because the capsule
(A) resists phagocytosis (B) is an endotoxins (C) destroys host tissue (D) is an exotoxin
Ans: A
64. Helicobacter pylori uses urease to counteract a chemical defense in the human organ in which it lives. This chemical defense is against (A) lysozyme (B) hydrochloric acid (C) superoxide radicals (D) sebum
Ans: B
65. Worldwide, the primary method for transmitting HIV is
(A) homosexual sex (B) heterosexual sex (C) use of injecting drugs (D) blood transfusions
Ans: B
66. Bacteria without cell wall belong to
(A) Mycoplasma (B) Rickettsia (C) Bacteroidetes (D) Halophiles
Ans: A
67. The enzyme useful in the conversion of penicillin G to 6-aminopenicillanic acid (6-APA)
(A) penicillin acylase (B) penicillinase (C) carboxypeptidase (D) aminopeptidase
Ans: A
68. When E.coli is grown in the presence of both Glucose and Lactose, glucose is first metabolised followed by lactose. This is referred to as (A) Positive induction (B) Catabolite repression (C) Cometabolism (D) Constitutive gene expression
Ans: B
69. Endotoxin is responsible for symptoms caused by
(A) Neisseria meningitidis (B) Streptococcus pyogenes
(C) Listeria monocytogenes (D) Clostridium tetani
Ans: A
70. A patient with nausea, vomiting and diarrhea within 5 hours after eating most likely has
(A) shigellosis (B) cholera
(C) E. coli gastroenteritis (D) staphylococcal food poisoning
Ans: D
71. A technique based on sedimentation is
(A) Electrophoresis (B) Centrifugation (C) Chromatography (D) Spectrophometry
Ans: B
72. Which is a correct match between the PCR step and the temperature used?
(A) Annealing : 94-96 degree C (B) Denaturation : 60-65 degree C (C) Extension : 70-72 degree C (D) Hold : 37 degree C
Ans: C
73. A technique for detecting chromosome number abnormalities in cancer is
(A) Pedigree analysis (B) Karyotyping (C) PCR (D) ELISA
Ans: B
74. MALDI TOF is useful for
(A) DNA fingerprinting (B) Peptide fingerprinting (C) Studying protein DNA interactions (D) Analysis of DNA methylation
Ans: B
75. Two bacteria show DNA:DNA hybridization of 75% . It may be concluded that
(A) They are same strains (B) They are same species
(C) They are same genus but different species (D) They are neither same genus nor same species
Ans: B
76. Which of the following trace element is particularly essential for nitrogen fixation?
(A) Nickel (B) Molybdenum (C) Zinc (D) Copper
Ans: B
77. Which of the following techniques DOES NOT involve PCR?
(A) ARISA (B) T-RFLP (C) FAME (D) DGGE
Ans: C
78. Which of the following is mycorrhizal biofertilizer?
(A) Nostoc (B) Anabaena (C) Glomus (D) Rhizobium
Ans: C
79. “Avirulence” genes are
(A) Present in the plant pathogen and cause disease in plants (B) Present in the plant pathogen and cause defense induction in plants
(C) Present in the plant and cause resistance to pathogen attack (D) Present in the plant and make them susceptible to pathogen attack
Ans: B
80. Which is an INCORRECT match between the scientist and their contribution I the field of Microbiology?
(A) Robert Hooke : discovery of causative agents for TB and anthrax (B) Joseph Lister : Antiseptic methods during surgery (C) Antoni van Leeuwenhoek : discovery of bacteria (D) Martinus Beijerinck : Discovery of Nitrogen fixation
Ans: A
81. The fluorescence dye DAPI can stain cells because it binds to
(A) Cell wall (B) Proteins (C) DNA (D) Cell membrane
Ans: C
82. A Nobel Laureate who received the prize for discovery of prions is
(A) David Baltimore (B) Stanley Prusiner (C) Harold Varmus (D) Barry Marshall
Ans: B
83. A process by which introduction of excess mineral nutrients in a water body leads to dense growth of plants and algae leading to environmental deterioration is
(A) Biomagnification (B) Eutrophication (C) Bioaccumulation (D) Bioconcentration
Ans: B
84. Which group of microorganisms was responsible for generation of molecular oxygen in the primitive Earth atmosphere?
(A) Proteobacteria (B) Cyanobacteria (C) Actinomycetes (D) Methanogens
Ans: B
85. Confocal Microscopy involves
(A) Laser beams (B) Fluorescence dyes (C) Live specimens (D) All of the above
Ans: D
86. Which is an example of a retrovirus?
(A) Herpesvirus (B) HIV (C) Influenza virus (D) Polio virus
Ans: B
87. CRISPR sequences are
(A) Located on the bacterial genome (B) Present in viral genome
(C) Encode various functional proteins that help viral replication (D) Derived by lateral transfer
Ans: A
88. The common feature of CRISPR-Cas9 and TALENS is that
(A) They originate from viruses (B) They act through guide RNA
(C) They can be used for genome editing (D) All of the above
Ans: C
89. What is the earliest step in the entry of HIV into the target human cell?
(A) Fusion of envelope with cell membrane (B) Binding of env protein to CD4 receptor
(C) Phagocytosis of the viral particle (D) Binding of coreceptor with env protein
Ans: B
90. RNA-dependent RNA polymerase is found in
(A) Double stranded DNA viruses
(B) Single stranded DNA viruses (C) RNA viruses (D) Retroviruses
Ans: C
91. A cluster of genes under a common promoter is known as
(A) Regulon (B) Operator (C) Transposon (D) Operon
Ans: D
92. Mutations in lac repressor can lead to
(A) Constitutive expression (B) Uninducible phenotype (C) Super repressor (D) Any of the above
Ans: D
93. IPTG is a gratuitous inducer. This means
(A) It is artificial and not natural (B) It is transported freely across the membrane
(C) It causes induction but does not get metabolized (D) It was discovered by chance
Ans: C