MCQs on Sterilization, Culture Media and Techniques for Staff Nurse and Medical Exams

1. The medium used in membrane filter technique was
a. EMB agar
b. EMR-Vp medium
c. Lactose broth
d. Endo agar


2. Lysol is a
a. Sterilent
b. Disinfectant
c. Antiseptic
d. Antifungal agent


3. Which of the following is a neutral stain?
a. Picric acid
b. Gmiemsa
c. Neutral red
d. Malachite green


4. Peptone water medium is an example for
a. Synthetic medium
b. Semisynthetic medium
c. Differential medium
d. None of these


5. The method in which the cells are frozen dehydrated is called
a. Pasteurization
b. Dessication
c. Disinfection
d. Lypophilization


6. The technique used to avoid all microorganisms is accomplished by
a. Sterlization
b. Disinfection
c. Surgical sterilization
d. Disinfection Sterilization


7. Thermal death time is
a. Time required to kill all cells at a given temperature
b. Temperature that kills all cells in a given time
c. Time and temperature needed to kill all cells
d. All of the above


8. A culture medium the exact composition of which is not known was called as
a. Simple
b. Complex
c. Defined
d. Natural


9. Elek’s gel diffusion test is used for the detection of
a. Tetani toxin
b. Cholera toxin
c. Diophtheria toxin
d. Toxoid


10. Temperature required for pasteurization is
a. Above 150oC
b. Below 100oC
c. 110oC
d. None of these

11. Separation of a single bacterial colony is calle
a. Isolation
b. Separation
c. Pure culturing
d. All of these


12. Which of the following is ionizing radiation?
a. U.V. rays
b. IR
c. ?-rays
d. None of these


13. Which of the following induces dimerisation of thymine?
a. X-rays
b. U.V. rays
c. ã-rays
d. None of these


14. When food material are preserved at a temperature just above freezing temperature, the process is called.
a. Freezing
b. Pasteurisation
c. Chilling
d. Frosting


15. Which of the following method of sterilization has no effect on spores?
a. Drying
b. Hot air oven
c. Autoclave
d. None of these


16. Treponema pallidum can be best indentified using
a. Fluorescence microscope
b. Bright field microscope
c. Dark field microscope
d. Flourescence microscope


17. Autoclaving is carried at
a. Dry heat
b. Atmospheric pressure
c. 120oC
d. All of these


18. Temperature in pasteurization is
a. 62.8oC
b. 35.7oC
c. 68.2oC
d. 60.8oC


19. The bacterial culture prepared by pure culture method is
a. Inoculum
b. Suspension
c. Dilution
d. None of these


20. Algae are rich in
a. Carbohydrates
b. Proteins
c. Vitamins
d. All of these

21. L-Lysine is produced from
a. Corynebacterium glutamicum
b. Clostridium botulinum
c. Mycobacterium sps
d. Pseudomonas


22. The orderly increase in the quantity of all of the cellular components is known as
a. Reproduction
b. Growth
c. Binary fission
d. None of these


23. Theobacillus thio oxidans grow at pH
a. 7.0
b. 1.0
c. 6.0
d. 9.5


24. Slow freezing requires the conditions
a. 0oC to 15oC for 15 min.
b. – 6 oC to – 10oC for 10 min.
c. – 15oC to 3 to 72 hrs.
d. None of these


25. Discontinuous heating is called
a. Pasteurization
b. Sterilization
c. Fermentation
d. Tindalisation


26. Isolation is
a. Purification of culture
b. Introduction of inoculum
c. Separation of a single colony
d. To grow microorganisms on surfaces


27. The condition required for autoclave
a. 121oC temp.and 15 lbs. pressure for 20 min.
b. 120oC temp.and 20 lbs. pressure for 30 min
c. 150oC temp.for 1 hr.
d. 130oC temp for 2 hr.


28. Lysozyme is effective against
a. Gram negative bacteria
b. Gram positive bacteria
c. Protozoa
d. Helminthes


29. Blood agar medium is
a. Enrichment medium
b. Enriched medium
c. Selective medium
d. Differential medium


30. Infrared radiation is a method of sterilization by
a. Dry heat
b. Moist heat
c. Chemical method
d. Mechanical method

31. Lyophilization means
a. Sterilization
b. Freeze-drying
c. Burning to ashes
d. Exposure to formation


32. Temperature used for hot air oven is
a. 100oC for 1 hour
b. 120oC for 1 hour
c. 160oC for 1 hour
d. 60oC for 1 hour


33. Phenol co-efficient indicates
a. Efficiency of a disinfectant
b. Dilution of a disinfectant
c. Purity of a disinfectant
d. Quantity of a disinfectant


34. This is an agar plate method and is commonly used for estimation of the number of bacteria in milk.
a. Standard Plate Count (SPC)
b. Spread plate
c. Lawn culture
d. Roll tube method


35. Agar is obtained form
a. Brown algae
b. Red algae
c. Green algae
d. Blue-green algae


36. A gram positive organism which produces swarming on culture medium is
a. Salmonella
b. Clostridium
c. Staphylococci
d. Proteus


37. Enhancement of virulence in bacteria is known as
a. Pathogenicity
b. Attenuation
c. Exaltation
d. Toxigenicity


38. For effective sterilization in an autoclave the temperature obtained is
a. 50oC
b. 100oC
c. 120oC
d. 180oC


39. Spores are killed by
a. 70% alcohol
b. Glutaraldehyde
c. Autoclaving
d. Both b and c


40. Glassware are sterilized by
a. Autoclaving
b. Hot air over
c. Incineration
d. None of these

41. Tyndallisation was proposed by
a. Tyndall
b. Pasteur
c. Koch
d. Jenner


42. Viruses can be cultivated in
a. Lab media
b. Broth
c. Living cells
d. None of these


43. By pasteurization
a. All the microorganisms can be removed
b. Only pathogenic forms can be removed
c. Only non-pathogenic forms can be removed
d. All of these are correct


44. The temperature required for pasteurization is
a. Above 100oC
b. Below 100oC
c. 100oC
d. None of these


45. In the medium other than nutrients, if any substance is used in excess, that medium is
a. Enriched medium
b. Special medium
c. Enrichment medium
d. None of these


46. Example for indicator medium is
a. Nutrient Agar
b. Nutrient broth
c. Wilson and Blair
d. Czapeck-dox medium


47. Example of Anaerobic medium is
a. Robertson cooked-meat medium
b. Nutrient agar
c. Nutrient broth
d. Mac-Conkey’s agar


48. The differentiate lactose and non-lactose fermentors, the medium used is
a. Wilson & lair
b. Blood Agar
c. Tetra thionate broth
d. Mac-Conkey’s Agar


49. Best method for getting pure culture is
a. Streak-plate
b. Agar slant
c. Both a & b
d. None of these


50. To transfer cultures from one place to another, the device used is
a. Slant
b. Needle
c. Inoculation loop
d. Autoclave

51. The bacterial culture prepared by pure culture is
a. Inoculum
b. Suspension
c. Dilution
d. None of these


52. Separation of a single colony is
a. Pure-culturing
b. Isolation
c. Separation
d. Both a and b


53. Growth period of the culture is
a. Inoculation
b. Incubation
c. Incineration
d. Isolation


54. At the temperature 160oC for one hour, complete sterilization occurs in
a. Autoclave
b. Hot air oven
c. Laminar flow
d. Incubator


55. In autoclave, the principle involved is
a. Dry heat
b. Moist heat
c. Steam under pressur
d. Both b and c


56. The spores of th bacteria which can withstand the moist heat effect also
a. Bacillus subtilis
b. Coxiella burnetti
c. Bacillus stearothermophilus
d. Pseudomonas


57. Factors on which disinfectivity of a disinfectant depends
a. Concentration of the substance
b. Time of action
c. pH of the medium and temperature suitable for the chemical
d. All of the above


58. Aldehydes, which are most powerful disinfectants
a. Formaldehyde
b. Acetaldehyde
c. Glutamal aldehyde
d. Both a and c


59. Accridine dyes are more effective against
a. Gram positive
b. Gram negative
c. Mycoplasmas
d. Rickttsiae


60. The sterilizing agent is
a. Ethelene oxide
b. Oxygen
c. Nitrogen
d. Carbon tetrachloride

61. Salts of heavy metals used as disinfectants are
a. Thiomersal
b. Phenyl mercury nitrate
c. Mercurochrome
d. All of these


62. Cultures are prepared by penetrating the inoculation loop with suspension into the medium, they are
a. Stock cultures
b. Stabcultures
c. Sub-cultures
d. None of these


63. The principle involved in the streak plate method is
a. Separation
b. Streaking
c. Isolation
d. Dilution


64. Culture media for fungi are
a. Potato dextrose agar (PDA)
b. Sabouraud’s agar
c. Czapekdox agar
d. All of the above


65. Spores of actinomycetes are very sensitive, killed at room temperature of
a. 52oC for 30 min.
b. 65oC for 30 min.
c. 70oC for 30 min.
d. 43oC for 30 min.


66. The term that is used for the bacteria which can withstand pasteurization but does not grow at higher temperatures
a. Thermophiles
b. Extreme thermophiles
c. Thermoduric
d. Facultative thermophiles


67. A common laboratory method of cultivating anaerobic micro-organisms is
a. Gas pack system
b. Brewer jar system
c. Pyrogallic acid over the cotton
d. None of these


68. Alkaliphiles grow at pH value between
a. 1 to 6
b. 6 to 9
c. 1 to 11
d. 7 to 12


69. The micro-organisms grow at high salinity are
a. Osmophiles
b. Halophiles
c. Both a and b
d. None of these


70. Non-lactose fermenting colonies seen on Mac Conkey’s medium are
a. Salmonella typhi
b. Escherichia coli
c. Klebsiella pneumoniae
d. Shigella shigae

71. Wilson and Blair medium is used for isolation of
a. Staphylococci
b. Salmonella typhosa
c. Vibrio cholerae
d. Shigella shigae


72. Laboratory diagnosis of enteric fever is based on
a. Blood culture
b. Urine and stool culture
c. Widal test
d. All of the above


73. Shigella was first isolated by
a. Shiga
b. Schmitz
c. Sonnei
d. Robert Koch


74. Which of the following are gas producing Salmonella?
a. S.typhi
b. S.enteritidis
c. S.cholerasuis
d. S.typhimurium


75. Kauffmann white scheme is used to detect
a. Salmonella spp.
b. Shigella spp.
c. E.coli
d. None of these


76. On Mac Conkey’s medium Esch. Coli forms
a. Colorless colonies
b. Greenish pigmentation
c. Pink coloured colonies
d. Medusa head appearance


77. C.diphtheriae requires
a. LJ medium
b. Mac Conkey’s medium
c. Potassium tellurite medium
d. PDA medium


78. Culture medium for Mycobacterium tuberculosis
a. L J medium
b. Mac Conkey’s medium
c. Wilson blair medium
d. None of these


79. Lepra bacillus is best cultured on
a. Armadillo’s brain
b. Foot pad of mice
c. Liver of guinea pig
d. Any of the above


80. Culture medium for clostridia spp.
a. 76 Lower stein Jensen’s medium
b. Mac Conkey’s medium
c. Robertson’s cooked meat medium
d. None of these

81. Clsotridium welchii is positive for
a. Elek’s gel precipitation test
b. Nagler’s test
c. Weil felix test
d. Bacitracin test


82. Nagler’s reaction detects
a. Coagulase
b. Hyaluronidase
c. Lecithinase
d. None of these


83. Incubation period of Cl. welchii is
a. 8-12 hours
b. 7-10 hours
c. 5-7 hours
d. 2-4 hours


84. The average incubation period of tetanus is
a. 2-3 days
b. 7-10 days
c. 14-21 days
d. 3-4 weeks


85. Salt agar is used for
a. Streptococcus
b. Staphylococcus
c. Vibrio
d. Shigella


86. Culture medium of Leishmania is
a. Sabousand’s medium
b. NNN medium
c. Wilson Blair medium
d. Czapek – dox medium


87. A simple asexual spore which develops by budding is known as
a. Chlamydospore
b. Blastospore
c. Arthospore
d. Conidia


88. Culture medium used for fungus is
a. Sabouraud’s medium
b. Nutrient agar
c. Nutrient broth
d. Minimal agar medium


89. For sterilization of fermentation equipment the method followed is
a. Radiation
b. Chemicals
c. Heating
d. All of these


90. D.pneumoniae can be cultivated in
a. Glucose broth
b. Serum broth
c. Agar and blood agar
d. Chocolate agar
e. All of these

91. D.pneumoniae can be identified by
a. Microscopic exam
b. Culture of sputum/blood
c. Animal inoculation
d. All of these
e. None of these


92. The diagnosis of tuberculosis is carried out by
a. Emulator
b. Antiformin method
c. Petroff’s method
d. Concentration method
e. All of these


93. The size of the virus can be determined by
a. Micrography
b. Ultra-centrifugation at high speed
c. Ultra-filteration
d. All of these


94. Differential staining of bacteria spore is related to
a. Albert’s staining
b. Lugol’ s staining
c. Moller’s staining
d. Indian ink preparation


95. Electron microscope studies does not help in identifying the section of bacterial spore
a. Core
b. Spore cortex
c. Capsule
d. All of these

Go to next Page:

Part 1Part 2Part 3Part 4Part 5Part 6Part 7Part 8Part 9Part 10