1. For the examination of microbial cells we require the use of?
A) High-power microscope
B) Low-power microscope
C) High-power microscope at a magnification of about 1,000 diameters
D) Low-power microscope at a magnification of about 1,000 diameters
ANSWER: C
2. Which microorganism(s) among the following perform photosynthesis by utilizing light?
A) Cyanobacteria
B) Fungi
C) Viruses
D) Cyanobacteria, Fungi and Viruses
ANSWER: A
3. The DNA molecule of microorganisms is made up of base pairs of ______
A) guanine-cytosine
B) adenine-thymine
C) adenine-cytosine
D) guanine-cytosine and adenine-thymine
ANSWER: D
4. Plamids are circular DNA molecules capable of autonomous replication.
A) True
B) False
ANSWER: A
5. Type strain is used for referring to?
A) species
B) genus
C) family
D) division ANSWER: A
6. The correct order of taxonomic groups from higher to lower rank is?
A) Kingdom—Order—Class—Family
B) Order—Class—Division—Family—Genus—Species
C) Kingdom—Order—Division—Family—Class—Genus—Species
D) Kingdom—Division—Class—Order—Family—Genus—Species
ANSWER: D
6. What are ribosomes composed of?
A) Proteins
B) DNA
C) RNA
D) Proteins and RNA
ANSWER: D
7. Which among the following come under Gram-positive eubacteria?
A) Clostridium
B) Actinomyces
C) Rhizobium
D) Clostridium,Actinomyces
ANSWER: D
8. Which among the following kingdoms were proposed by Whittaker?
A) Monera
B) Protista,Fungi
C) Plantae,Animalia
D) Monera,Protista,Fungi,Plantae,Animalia
ANSWER: D
9. According to Bergey’s Manual of Systematic Bacteriology, prokaryotes that lack a cell wall belong to the group?
A) Gracilicutes
B) Firmicutes
C) Tenericutes
D) Mendosicutes
ANSWER: C
10. Which part of the compound microscope helps in gathering and focusing light rays on the specimen to be viewed?
A) Eyepiece lens
B) Objective lens
C) Condenser lens
D) Magnifying lens
ANSWER: C
11. What is the minimum distance for the eye to focus any object?
A) 11 cm
B) 25 cm
C) 32 cm
D) 42 cm
ANSWER: B
12. Resolving power of a microscope is a function of______
A) Wavelength of light used
B) Numerical aperture of lens system
C) Refractive index
D) Wavelength of light used and numerical aperture of lens system
ANSWER: D
13. The greatest resolution in light microscopy can be obtained with ______
A) Longest wavelength of visible light used B) An objective with minimum numerical aperture
C) Shortest wavelength of visible light used
D) Shortest wavelength of visible light used and an objective with the maximum numerical aperture
ANSWER: D
14. Oil immersion objective lens has an NA value of______
A) 0.65
B) 0.85
C) 1.33
D) 1.00
ANSWER: C
15. In fluorescence microscopy, which of the following performs the function of removing all light except the blue light?
A) Exciter filter
B) Barrier filter
C) Dichroic mirror
D) Mercury arc lamp
ANSWER: A
16. Total Magnification is obtained by______
A) Magnifying power of the objective lens
B) Magnifying power of eyepiece
C) Magnifying power of condenser lens
D) Magnifying power of both the objective lens and eyepiece
ANSWER: D
17. In light microscopy, which of the following is used as fixatives prior to staining technique?
A) Osmic acid
B) Glutaraldehyde
C) Heat D) Osmic acid, glutaraldehyde, heat
ANSWER: C
18. In Phase contrast microscopy, the rate at which light enters through objects is______
A) Constant
B) Inversely proportional to their refractive indices
C) Directly proportional to their refractive indices
D) Exponentially related to their refractive indices
ANSWER: B
19. Which part of the light microscope controls the intensity of light entering the viewing area?
A) Coarse adjustment screw
B) Fine adjustment screw
C) Diaphragm
D) Condenser lens
Answer: c
20.Which of the following is used in electron microscope?
A) electron beams
B) magnetic fields
C) light waves
D) electron beams and magnetic fields
ANSWER: D
21. Electron Microscope can give a magnification up to ______
A) 400,000X
B) 100,000X
C) 15000X
D) 100X
ANSWER: A
22. Which of the following are true for electron microscopy?
A) specimen should be thin and dry
B) image is obtained on a phosphorescent screen
C) electron beam must pass through evacuated chamber
D) specimen should be thin and dry, image is obtained on a phosphorescent screen and electron beam must pass through evacuated chamber
ANSWER: D
23. Which among the following helps us in getting a three-dimensional picture of the specimen?
A) Transmission Electron Microscope
B) Scanning Electron Microscope
C) Compound Microscope
D) Simple Microscope
ANSWER: B
24. The secondary electrons radiated back in scanning microscope is collected by?
A) specimen
B) anode
C) vacuum chamber
D) cathode
ANSWER: B
25. Which of the following techniques are used in Transmission Electron Microscopy (TEM) for examining cellular structure?
A) Negative-Staining
B) Shadow Casting
C) Ultrathin Sectioning
D) Negative-Staining, Shadow Casting, Ultrathin Sectioning, Freeze-Etching
ANSWER: D
26. The dye eosinate of methylene blue belongs to which group?
A) Acidic dye B) Basic dye
C) Neutral dye
D) Oxazine dye
ANSWER: C
27. What is the correct order of staining reagents in Gram-Staining?
A) Crystal violet, alcohol, iodine solution, safranin
B) Crystal violet, iodine solution, alcohol, safranin
C) Crystal violet, safranin, alcohol, iodine solution
D) Iodine solution, crystal violet, alcohol, safranin
ANSWER: B
28. Which bacteria appears purple-violet colour after staining?
A) Gram-positive
B) Gram-negative
C) Both Gram-positive and Gram-negative
D) Neither Gram-positive nor Gram-negative
ANSWER: A
29. Which of the following are true for Gram-negative bacteria?
A) upon alcohol treatment, the permeability of the cell wall increases
B) crystal violet-iodine (CV-I) complex is extracted
C) pore size decreases and the CV-I complex cannot be extracted
D) alcohol treatment increases the permeability of the cell wall and the CV-I complex can be extracted
ANSWER: D
30. Gram-positive bacteria are usually more susceptible to?
A) streptomycin
B) tetracyclin
C) penicillin D) ampicillin
ANSWER: C
31. Which of the staining technique helps in demonstrating spore structure in bacteria as well as free spores?
A) Acid-fast stain
B) Endospore stain
C) Capsule stain
D) Flagella stain
ANSWER: B
32. In Gram-staining, iodine is used as a______
A) fixative
B) mordant
C) solublizer
D) stain
ANSWER: B
33. Which of the following is the example of Gram-negative bacteria?
A) Lactobacillus
B) Eschericia coli
C) Staphylococcus aureus
D) Bacillus subtilis
ANSWER: B
34. In the classification of bacteria according to shape,which among the following refer to cuboidal arrangement of bacterial cells?
A) Tetrads
B) Staphylococci
C) Sarcinae
D) Streptococci
ANSWER: C
35. Which group of bacteria among the following have the largest area of contact?
A) Palisades
B) Trichomes
C) Streptobacilli
D) Diplobacilli
ANSWER: B
36. Which among the following are “Spirochetes”?
A) Spirillum volutans
B) Corynebacterium diphtheriae
C) Streptomyces sp.
D) Treponema pallidum
ANSWER: D
37. What is the approximate size of the bacterial cell?
A) 2mm in diameter
B) 1mm in diameter
C) 2 micrometer in diameter
D) 0.5 to 1.0 micrometer in diameter
ANSWER: D
38. When rod shaped bacteria appears in pairs,it is known as?
A) Diplobacilli
B) Streptobacilli
C) Diplococci
D) Staphylococci
ANSWER: A
39. Surface area/volume ratio of bacteria is exceedingly low compared to the same ratio for larger organisms of similar shape. A) True
B) False
ANSWER: B
40. Bacteria with less than a complete twist or comma shaped is known as?
A) spirilla
B) helical
C) vibrioid
D) spirochetes
ANSWER: C
41. Which of the following are functions of stalk?
A) nutrient absorption
B) motility
C) attachment of the cells to surfaces
D) human infection
ANSWER: C
42. Bacteria having cluster of flagella at both poles of cells are known as?
A) Lophotrichous
B) Peritrichous
C) Amphitrichous
D) Monotrichous
ANSWER: C
43. Salmonella typhi has which type of flagella arrangement?
A) Amphitrichous
B) Peritrichous
C) Monotrichous
D) Lophotrichous
ANSWER: B
44. The L Ring in a Gram-Negative bacterium flagella is associated with______
A) Peptidogycan
B) Outer Membrane
C) Cytoplasmic Membrane
ANSWER: B
45. Which among the following acts as a transport protein for protons in flagellar motion?
A) fli protein
B) cGMP
C) atp
D) mot protein
ANSWER: D
46. F pilus has a major role as______
A) motility of the cell
B) port of entry of genetic material during mating
C) attachment to host cell
D) human infection
ANSWER: B
47. When a bacteria swim towards a chemical, it is termed as______
A) positive chemotaxis
B) phototaxis
C) negative chemotaxis
D) magnetotaxis
ANSWER: A
48. Which type of force drives the flagellar motion?
A) Protonmotive force B) ATP driven
C) Protonmotive and ATP driven
D) No protonmotive nor ATP driven
ANSWER: A
49. Peptidoglycan layer is present in large quantity in?
A) Gram-positive bacteria
B) Gram-negative bacteria
C) Fungi
D) Algae
ANSWER: A
50. Peptidoglycan is made up of ______
A) N-acetylglucosamine
B) N-acetylmuramic acid
C) N-acetylglucosamine, N-acetylmuramic acid
D) N-acetylglucosamine,N-acetylmuramic acid,amino acids
ANSWER: D
51. Teichoic acid present in Gram-positive bacteria can bind to which ion?
A) Fe ions
B) Phosphorus ions
C) Mg ions
D) Sulphur ions
ANSWER: C
52. The outer membarane of the Gram-negative cell wall is anchored to the underlying peptidoglycan by means of which of the following?
A) Braun’s Lipoprotein
B) Phospholipids
C) Proteins D) Lipopolysaccharide
ANSWER: A
53. Which among the following acts as receptors for bacteriophage attachment in Gram-negative bacteria?
A) Cilia
B) O antigens
C) Lipid A
D) Teichoic acid
ANSWER: B
54. Porins are special proteins act as channels in outer membrane of Gram-negative bacteria.
A) True
B) False
ANSWER: A
55. NAG and NAM of peptidoglycan layer is linked by ______
A) beta-(1,4) glycosidic linkage
B) alpha-(1,4) glycosidic linkage
C) alpha-(1,6) glycosidic linkage
D) beta-(1,6) glycosidic linkage
ANSWER: A
56. Gram-negative bacteria are more resistant to antibiotics due to the presence of?
A) Thin peptidoglycan wall
B) Outer lipopolysaccharide layer
C) Porin proteins
D) Teichoic acid
ANSWER: B
57. Which of the following are present in teichoic acids? A) ribitol residues
B) glycerol residues
C) glucose residues
D) ribitol or glycerol residues
ANSWER: D
58. Which among the following is associated with export of exocellular enzymes?
A) central mesosomes
B) peripheral mesosomes
C) thylakoids
D) nucleus
ANSWER: B
59. Ribosomes of prokaryotes have a sedimentation coefficient of?
A) 90S
B) 80S
C) 50S
D) 70S
ANSWER: D
60. Which among the following compound when added to cytoplasmic membrane helps in maintaining the rigidity of cell?
A) lipopolysaccharide
B) hopanoid
C) phosphoglycerides
D) amino acids
ANSWER: B
61. The nucleoid can be made visible under the light microscope by ______
A) Methylene blue
B) Iodine C) Nile blue
D) Feulgen staining
ANSWER: D
62. What helps in the heat resistance of endospore?
A) calcium-DPA complex
B) water
C) methylene
D) calcium
ANSWER: A
63. Cysts also have high heat resistance like endospores.
A) True
B) False
ANSWER: B
64. Which of the following are true for cytoplasmic membrane?
A) hydrophilic barrier
B) hydrophobic barrier
C) site of generation of protonmotive force
D) hydrophobic barrier and site of generation of protonmotive force
ANSWER: D
65. The organisms which can use reduced inorganic compounds as electron donors are known as ______
A) chemotrophs
B) organotrophs
C) lithotrophs
D) phototrophs
ANSWER: C
66. Which of the following is nutritional characterization of Escherichia coli?
A) Chemotrophic
B) Organotrophic
C) Autotrophic
D) Chemotrophic, Organotrophic, Heterotrophic
ANSWER: D
67. Which of the following amino acids require sulphur for their synthesis?
A) tryptophan
B) methionine
C) cystine
D) methionine and cystine
ANSWER: D
68. Which of the following are trace elements?
A) Potassium ion
B) Sodium ion
C) Copper ion
D) Magnesium ion
ANSWER: C
69.”Red extreme halophiles”, are members of the archaebacterial which cannot grow with less than 12 to 15 percent NaCl.
A) True
B) False
ANSWER: A
70. Which of the following are functions of water in the culture medium?
A) nutrients must be in aqueous solution
B) cofactor of enzymes
C) provides resistance to sudden transient temperature changes D) it is a chemical reactant, nutrients must also be present in aqueous solution and provides resistance to sudden temperature changes.
ANSWER:D
71.Which of the following bacteria can grow both as chemolithotrophs or as chemoorganotrophs?
A) Nitrosomonas sp.
B) Pseudomonas pseudoflava
C) Rhodospirillum rubrum
D) Chromatium okenii
ANSWER: B
72. Which of the following is a characteristic of beef extract?
A) product resulting from the digestion of proteinaceous materials
B) aqueous extract of lean beef tissue
C) aqueous extract of yeast cells
D) complex carbohydrate obtained from certain marine algae
ANSWER: B
73. Which of the following is used as a solidifying agent for media?
A) Beef extract
B) Peptone
C) Agar
D) Yeast extract
ANSWER: C
74. Which of the following is a rich source of B vitamins?
A) Peptone
B) Yeast extract
C) Beef extract
D) Agar
ANSWER: B
75. The isolation of gonorrhea-causing organism, Neisseria gonorrhoeae by the use of certain antibiotics in media is an example of which of the following?
A) Selective media
B) Differential media
C) Enriched media
D) Assay media
ANSWER: A
76. Nutrient broth, a liquid media contains beef extract and peptone respectively in how much amounts?
A) 0.2%, 0.4%
B) 0.1%, 0.6%
C) 0.3%, 0.5%
D) 0.7%, 0.3%
ANSWER: C
77. Which of the following instrument is used for sterilizing the media after it has been prepared?
A) Autoclave
B) Laminar Air Flow Chamber
C) Inoculum Needle
D) Incubator
ANSWER: A
78. Colony formation can be observed in liquid media broth.
A)True
B) False
ANSWER: B
79. Which of the following is a Complex media for fungal growth?
A) Nutrient broth
B) Luria-Bertani media C) Potato Dextrose Agar(PDA) media
D) Mac Conkey Agar media
ANSWER: C
80. Which of the following are functions of Maintenance Media?
A) used for assay of vitamins,amino acids
B) used for determining the bacterial content
C) used for determining the type of growth produced by bacteria
D) used for the maintenance of the viability and physiological characteristics
ANSWER: D
81. Which of the following bacteria requires nicotinic acid as a growth factor in their media?
A) Proteus vulgaris
B) Nitrosomonas sp.
C) E. coli
D) Leuconostoc mesenteroides
ANSWER: A
82. The temperature that allows for most rapid growth during a short period of time is known as ______
A) Minimum Temperature
B) Maximum Temperature
C) Optimum Temperature
D) Growth Temperature
Answer: C
83. Mesophiles are group of bacteria that grow within the temperature range of?
A) 0-20 degree Celsius
B) 25-40 degree Celsius
C) 45-60 degree Celsius
D) more than 60 degree Celsius ANSWER: B
84. Which of the following factors are responsible for the stability of thermophiles at high temperatures?
A) increased leakage of cell components
B) presence of large no. of polar amino acids and alpha-helix protein
C) thermal stability of ribosomes
D) presence of Inositol diphosphate and thermal stability of ribosomes
ANSWER: D
85. The bacterium Staphylococcus aureus is which type of bacteria?
A) Psychrophile
B) Mesophile
C) Thermophile
D) Mesophile and psychrophile
ANSWER: B
86. The GasPak system is suitable for which of the following?
A) Aerobic bacteria
B) Anaerobic bacteria
C) Facultatively anaerobic bacteria
D) Microaerophilic bacteria
ANSWER: B
87. Which of the following are functions of phosphates used in the preparation of media?
A) they act as buffer
B) source of phosphorous
C) act as “reserve alkali”
D) they act as buffer and is a source of phosphorous
ANSWER: D
88. The optimum pH for the growth of most bacteria lies between______
A) 5-9
B) 6.5-7.5
C) 2-3.5
D) 9-9.5
ANSWER: B
89. The portion of the growth curve where a rapid growth of bacteria is observed is known as ______
A) Lag phase
B) Logarithmic phase
C) Stationary phase
D) Decline phase
ANSWER: B
90. The growth of bacterial population follows a geometric progression.
A) True
B) False
ANSWER: A
91. In the growth equation: n= 3.3 (log10 N – log10 No ), n stands for______
A) total population
B) initial population
C) number of generations
D) growth constant
ANSWER: C
92. Lag phase is also known as ______
A) period of initial adjustment
B) transitional period
C) generation time D) period of rapid growth
ANSWER: A
93. Which phase shows reproduction rate equal to the equivalent death rate?
A) Log phase
B) Stationary phase
C) Death phase
D) Lag phase
ANSWER: B
94. In pour-plate method,the medium should be maintained at what temperature?
A) 37 degree C
B) 67 degree C
C) 45 degree C
D) 0 degree C
ANSWER: C
95. Dilution of the mixed culture is a common step in all the three methods: the streak-plate,the spread-plate and the pour-plate technique.
A) True
B) False
ANSWER: B
96. Which of the following method can be used to determine the number of bacteria quantitatively?
A) Streak-plate
B) Spread-plate
C) Pour plate
D) Pour-plate and spread plate
ANSWER: D
98. Growth in broth cultures occurs mainly in the form of ______A) slightly turbid
B) heavy surface pellicle
C) sediment
D) viscous
ANSWER: B
99. Which of the following have peritrichous flagella?
A) Acetobacter
B) Gluconobacter
C) Agrobacteria
D) Rhizobium
ANSWER: A
100. Among the following which is positive for coagulase test?
A) Staphylococcus aureus
B) Staphylococcus epidermidis
C) Staphylococcus saprophyticus
D) E.coli
ANSWER: A
101. Which of the following is the causative agent of dental caries?
A) S.pneumoniae
B) S.pyogenes
C) S.mutans
D) S.faecalis
ANSWER: C
102. Which of the following genus of species play an active role in the decomposition of urea?
A) Bacillus
B) Sporosarcina
C) Clostridium D) Desulfotomaculum
ANSWER: B
103. Pseudomembranous colitis is a disease of ______
A) stomach
B) wounds
C) bowel
D) limbs
ANSWER: C
104. Which of the following genus of organisms are normal inhabitants of human mouth?
A) Agromyces
B) Arachnia
C) Actinomyces
D) Rothia
ANSWER: D
105. Sabouraud media for the growth of fungi is composed of ______
A) glucose and ammonia
B) maltose and peptone
C) sucrose and peptone
D) peptone
ANSWER: B
106. The optimum pH for the growth of fungi is ______
A) 7.8-9.0
B) 12-14
C) 3.8-5.6
D) 1.0-2.0
ANSWER: C
107. In which of the following categories of cancer solid tumors grow from derivatives of embryonal mesoderm?
A) Leukemias
B) Lymphomas
C) Sarcomas
D) Carcinomas
ANSWER: C
108. Anaplasia is structural abnormality of cells.
A) True
B) False
ANSWER: A
109. Which among the following is the family of RNA containing viruses that can cause cancer in animals?
A) Herpesviridae
B) Adenoviridae
C) Papovaviridae
D) Retroviridae
ANSWER: D
110. Cancer of the lip of mouth have been associated with ______
A) HSV1
B) HSV2
C) EBV
D) SV 40
ANSWER: A
111. Causative agent of tobacco mosaic disease was filterable.
A) True
B) False
ANSWER: A
112. Yellow fever virus can be attenuated by serial passage on cultures of ______
A) embryonated eggs
B) tissue
C) chick embryo tissue
D) pig embryo tissue
ANSWER: C
113. In which of the following situations will the logarithmic plot of survivors be constant?
A) physiological conditions are different
B) cells of microbial population vary in size
C) age and physiological conditions are uniform
D) temperature conditions are different
ANSWER: C
114. A suspension of E.coli exposed to a heat treatment may yield a greater number of survivors if a plating medium of ______is used.
A) peptone
B) trypticase soy agar
C) deoxycholate agar
D) potato dextrose
ANSWER: B
115. A high concentration of which of the following compounds in the material generally increases the thermal resistance of microorganisms?
A) proteins
B) carbohydrates
C) lipids
D) salts
ANSWER: B
116. Which of the following actions are not affected by antimicrobial agents?
A) cell wall synthesis
B) nucleic acid synthesis
C) protein synthesis
D) capsule formation
ANSWER: D
117. Zone of inhibition is observed in tube-dilution method.
A) True
B) False
ANSWER: B
118. Antibiotics are not effective against plant pathogens.
A) True
B) False
ANSWER: B
119. Which of the following carbohydrates are mainly present in whey?
A) glucose
B) lactose
C) fructose
D) sucrose
ANSWER: B
120. Diaminopimelic acid (DAP) is produced by which of the following microorganism?
A) E.coli
B) Enterobacter aerogenes
C) Bacillus subtilis
D) Streptococcus equisimilis
ANSWER: A
121. Insulin was isolated from which of the following organs of animals?
A) small intestine
B) tongue
C) pancreas
D) stomach
ANSWER: C
122. Which of the following is not a desired characteristic of the organism to be used for industrial application?
A) should produce less amount of product
B) should be readily available
C) should grow rapidly
D) should be nonpathogenic
ANSWER: A
123. Which among the following are not used as raw materials for alcohol production?
A) corn
B) molasses
C) whey
D) grapes
ANSWER: C
124. The leavening or rising of dough is due to which of the following gases?
A) oxygen
B) carbon dioxide
C) hydrogen
D) sulphur dioxide
ANSWER: B
125. Which of the following yeast can be used to produce microbial protein?
A) Saccharomyces cerevisiae B) Candida milleri
C) Eremothecium ashbyi
D) Candida utilis
ANSWER: D