MCQOPTIONS
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MCQOPTIONS
This section includes 229 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The third kingdom, protista, as suggested by E.H. Haeckel includes |
| A. | bacteria |
| B. | algae |
| C. | fungi |
| D. | all of these |
| Answer» E. | |
| 52. |
Which of the following is/are vapour-phase disinfectant/s? |
| A. | Formaldehyde |
| B. | Ethylene oxide |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» D. None of these | |
| 53. |
How much percentage of aqueous solution of phenol rapidly kills the vegetative cells of microorganisms? |
| A. | 1% |
| B. | 2% |
| C. | 5% |
| D. | 10% |
| Answer» D. 10% | |
| 54. |
Primary differences between cilia and flagella are |
| A. | arrangement of microtubules |
| B. | length and location of basal bodies |
| C. | how the microtubules are fused to each other |
| D. | number, length and direction of force |
| Answer» E. | |
| 55. |
Which were the investigators lived at the same time? |
| A. | Koch and Pasteur |
| B. | Darwin and Woese |
| C. | Van Leeuenhoek and Ricketts |
| D. | Berg and Hooke |
| Answer» B. Darwin and Woese | |
| 56. |
Which of the following material is sterilized by heating at 160°C in a hot air oven for one hour? |
| A. | Swab sticks |
| B. | All-glass syringes |
| C. | Oils and jellies |
| D. | All of these |
| Answer» E. | |
| 57. |
Which of the following best represents the hierarchy of levels of biological classification? |
| A. | Phylum, kingdom, class, order, genus, species, family |
| B. | Kingdom, phylum, class, order, family, genus, species |
| C. | Kingdom, phylum, family, class, order, genus, species |
| D. | Class, order, kingdom, phylum, family, genus, species |
| Answer» C. Kingdom, phylum, family, class, order, genus, species | |
| 58. |
Which of the following is an acridine dye? |
| A. | crystal violet |
| B. | malachite green |
| C. | tryptoflavine |
| D. | brilliant green |
| Answer» D. brilliant green | |
| 59. |
Microbes can be removed from a liquid solution by the process of |
| A. | filtration |
| B. | freeze-drying |
| C. | osmosis |
| D. | desiccation |
| Answer» B. freeze-drying | |
| 60. |
Cell theory includes all of the following except |
| A. | all organisms are composed of one or more cells |
| B. | the cell is the most primitive form of life |
| C. | the cell is the structural unit of life |
| D. | cells arise by division of preexisting cells |
| Answer» C. the cell is the structural unit of life | |
| 61. |
Which of the following agents cause death to the cell by coagulation of cytoplasmic proteins? |
| A. | Alcohol |
| B. | Dyes |
| C. | Chlorine |
| D. | Heavy metals |
| Answer» E. | |
| 62. |
The antimicrobial activity of phenolics is not reduced at which of the following conditions? |
| A. | acidic pH |
| B. | alkaline pH |
| C. | low temperatures |
| D. | presence of soap |
| Answer» E. | |
| 63. |
Which material is used for the Berkefeld filter? |
| A. | diatomaceous earth |
| B. | asbestos pad |
| C. | porcelain |
| D. | sintered glass disks |
| Answer» B. asbestos pad | |
| 64. |
Which of the following methods is used for determining the decrease in the amount of growth? |
| A. | test done on agar medium plate |
| B. | test done into an agar medium or broth |
| C. | test done by transfering water-soluble substances to sterile media |
| D. | by phenol-coefficient method |
| Answer» C. test done by transfering water-soluble substances to sterile media | |
| 65. |
The idea of selective toxicity was first proposed by |
| A. | Antony van Leeuwenhoek |
| B. | Paul Ehrlich |
| C. | Louis Pasteur |
| D. | Alexander Fleming |
| Answer» C. Louis Pasteur | |
| 66. |
Which of the following show the maximum resistance to physical and chemical agents? |
| A. | Viruses |
| B. | Mold spores |
| C. | Bacterial spores |
| D. | E.coli |
| Answer» D. E.coli | |
| 67. |
Most microbial structures and enzymes are composed of |
| A. | lipids |
| B. | proteins |
| C. | carbohydrates |
| D. | lipids and carbohydrates |
| Answer» C. carbohydrates | |
| 68. |
Which of the following is/are included in Kingdom Prokaryotae? |
| A. | Bacteria |
| B. | Protozoa |
| C. | Fungi |
| D. | All of these |
| Answer» B. Protozoa | |
| 69. |
The first organism in most natural food chains is |
| A. | a herbivore |
| B. | a decomposer |
| C. | photosynthetic |
| D. | carnivorous |
| Answer» B. a decomposer | |
| 70. |
Which of the following is a characteristic unique to the ciliates? |
| A. | Use of cilia as a sensory function |
| B. | Presence of both a macronucleus and several micronuclei |
| C. | Both (a) and (b) |
| D. | Possess a light-detecting eye spot |
| Answer» D. Possess a light-detecting eye spot | |
| 71. |
A newly discovered microscopic structure is hypothesized to be a living organism. Which of the following lines of evidence would support the contention that this organism may be alive? |
| A. | It contains DNA |
| B. | It is made of a single cell |
| C. | It utilizes energy |
| D. | All of these |
| Answer» D. All of these | |
| 72. |
Which of the following does not kill endospores? |
| A. | Autoclave |
| B. | Incineration |
| C. | Hot air sterilization |
| D. | Pasteurization |
| Answer» E. | |
| 73. |
Which cell type is considered to have the oldest ancestor? |
| A. | Archaea |
| B. | Bacteria |
| C. | Eukarya |
| D. | they all share the same ancestor |
| Answer» E. | |
| 74. |
Which of the following is most effective for sterilizing mattresses and plastic petri plates? |
| A. | Chlorine |
| B. | Ethylene oxide |
| C. | Glutaraldehyde |
| D. | Ultraviolet radiation |
| Answer» C. Glutaraldehyde | |
| 75. |
Which of the following is bactericidal? |
| A. | Membrane filtration |
| B. | Ionizing radiation |
| C. | Freeze-drying |
| D. | Deep freezing |
| Answer» C. Freeze-drying | |
| 76. |
The membranes of which domains are chemically the most similar? |
| A. | Archaea and Bacteria |
| B. | Bacteria and Eukarya |
| C. | Eukarya and Archaea |
| D. | membranes of all three domains are chemically identical |
| Answer» C. Eukarya and Archaea | |
| 77. |
Who was the inventor of the Petri dish? |
| A. | R.J. Petri, an assistant of R. Koch |
| B. | A famous French cook |
| C. | Italian glass blower from Petri, Italy |
| D. | None of the above |
| Answer» B. A famous French cook | |
| 78. |
Which of the following structures is the smallest? |
| A. | Viriod |
| B. | Hydrogen atom |
| C. | Bacterium |
| D. | Mitochondrion |
| Answer» C. Bacterium | |
| 79. |
Which of the following inhibits DNA replication? |
| A. | cathode rays |
| B. | UV light |
| C. | x-rays |
| D. | gamma rays |
| Answer» C. x-rays | |
| 80. |
Milk is pasteurized in batch method by keeping it at |
| A. | 63°C for 30 minutes |
| B. | 72°C for 60 seconds |
| C. | 73°C for 30 minutes |
| D. | 72°C for 6 minutes |
| Answer» B. 72°C for 60 seconds | |
| 81. |
Which of the following is not a chemical agent for microbial control? |
| A. | Radiations |
| B. | Antibiotics |
| C. | Antiseptics |
| D. | Germicide |
| Answer» B. Antibiotics | |
| 82. |
Which of the following compounds are commonly used as general antiseptics to treat cuts and scratches? |
| A. | Aldehydes |
| B. | Ethylene oxide |
| C. | Halogens |
| D. | None of these |
| Answer» D. None of these | |
| 83. |
Which of the following are generally applied on living animal tissues? |
| A. | Antiseptics |
| B. | Disinfectants |
| C. | Preservatives |
| D. | Sanitizer |
| Answer» B. Disinfectants | |
| 84. |
The Archaea include all of the following except |
| A. | methanogens |
| B. | halophiles |
| C. | thermoacidophiles |
| D. | cyanobacteria |
| Answer» E. | |
| 85. |
Ceepryn belongs to which of the following categories? |
| A. | Anionic detergents |
| B. | Cationic detergents |
| C. | Nonionic detergents |
| D. | Ammonium salts |
| Answer» C. Nonionic detergents | |
| 86. |
Which of the following describes the effect of ionizing radiation on microbes? |
| A. | Changes the 3-dimensional structure of proteins to a 2-dimen-sional form |
| B. | Substantially decreases enzymatic activity, slowing microbial reproduction |
| C. | Induces electrons and protons to jump out of the molecules of the microbe |
| D. | None of the above |
| Answer» D. None of the above | |
| 87. |
Eukaryotic cell organelles first emerged |
| A. | from a specialized lineage of cells within the kingdom Protista |
| B. | when prokaryotes engulfed each other and became interdependent |
| C. | when bacteria made their first attempts at reproduction |
| D. | just before the origin of the animal and fungal kingdoms |
| Answer» C. when bacteria made their first attempts at reproduction | |
| 88. |
Which of the following methods will not sterilize? |
| A. | Aqueous glutaraldehyde for 10 hours |
| B. | Dry heat at 171°C for 1 to 2 hours |
| C. | 121°C at 15 lb/in pressure for 15 to 20 minutes |
| D. | 100°C boiling water for 30 minutes |
| Answer» E. | |
| 89. |
Which of the following has most heat resistant spores? |
| A. | Clostridium histolyticum |
| B. | Clostridium perfringens |
| C. | Bacillus stearothermophilus |
| D. | Bacillus cereus |
| Answer» D. Bacillus cereus | |
| 90. |
Which among the following is an example of organic compound of mercury? |
| A. | Mercuric chloride |
| B. | Mercuric oxide |
| C. | Mercurochrome |
| D. | Ammoniated mercury |
| Answer» D. Ammoniated mercury | |
| 91. |
Which one is not studied in microbiology? |
| A. | Bacteria |
| B. | Animal behaviour |
| C. | Fungi |
| D. | Algae |
| Answer» C. Fungi | |
| 92. |
Preservation of foods by using salts and sugars works by |
| A. | raising pH |
| B. | lowering osmotic pressure |
| C. | creating a hypertonic environment |
| D. | creating a hypotonic environment |
| Answer» D. creating a hypotonic environment | |
| 93. |
All the following are basic properties of cells except |
| A. | cells have nuclei and mitochondria |
| B. | cells have a genetic programme and the means to use it |
| C. | cells are capable of producing more of themselves |
| D. | cells are able to respond to stimuli |
| Answer» B. cells have a genetic programme and the means to use it | |
| 94. |
Which of the following is not a disinfectant containing a heavy metal? |
| A. | Silver nitrate |
| B. | Mercurochrome |
| C. | Copper sulfate |
| D. | Chlorine |
| Answer» E. | |
| 95. |
The three domain version of life on earth is based on the |
| A. | nucleic acid sequence data |
| B. | morphological traits |
| C. | metabolic traits |
| D. | characteristics of the cell wall |
| Answer» B. morphological traits | |
| 96. |
Which of the following process can be efficiently carried out by incineration? |
| A. | Sterilization of scalpel blades and needles |
| B. | Sterilization of all glass syringes |
| C. | Sterilization of points of forceps |
| D. | Destruction of contaminated materials |
| Answer» E. | |
| 97. |
Complete destruction of the microorganisms is commonly known as |
| A. | disinfection |
| B. | sterilization |
| C. | antisepsis |
| D. | none of these |
| Answer» D. none of these | |
| 98. |
Sweet and salty foods frequently don't require refrigeration to prevent spoilage because they have |
| A. | insufficient nutrients |
| B. | low pH |
| C. | high concentration of solutes |
| D. | toxic alkaline chemicals |
| Answer» D. toxic alkaline chemicals | |
| 99. |
Chlorinated lime is the alternative name for __________________ |
| A. | Calcium hypochlorite |
| B. | Sodium hypochlorite |
| C. | Chloramine-T |
| D. | Azochloramide |
| Answer» B. Sodium hypochlorite | |
| 100. |
Which of the following skin disinfectant(s) is/are most frequently used? |
| A. | Isopropyl alcohol |
| B. | Ethyl alcohol |
| C. | Both (a) and (b) |
| D. | none of these |
| Answer» D. none of these | |