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.
| 151. |
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» D. Osmic acid, glutaraldehyde, heat | |
| 152. |
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» D. Condenser lens | |
| 153. |
Which of the following acts as a test organism in the procedure of phenol-coefficient method? |
| A. | Escherichia coli |
| B. | Streptococcus faecalis |
| C. | Staphylococcus aureus |
| D. | Lactobacillus |
| Answer» D. Lactobacillus | |
| 154. |
The individual best remembered for bringing microbes to the world is |
| A. | Robert Hooke |
| B. | Antony Van Leeuenhoek |
| C. | Robert Koch |
| D. | Masaki Ogata |
| Answer» C. Robert Koch | |
| 155. |
All of the following are features of prokaryotes except |
| A. | nitrogen fixation |
| B. | photosynthesis |
| C. | sexual reproduction |
| D. | locomotion |
| Answer» D. locomotion | |
| 156. |
How much time is required by spores of Clostridium botulinum to be killed by moist heat at 1200C? |
| A. | 2 hours |
| B. | 4 to 20 minutes |
| C. | 24 hours |
| D. | 6-7 hours |
| Answer» C. 24 hours | |
| 157. |
Which of the following methods is used for killing microorganisms of only certain types and not all microorganisms? |
| A. | Pasteurization |
| B. | Incineration |
| C. | Boiling water |
| D. | Fractional Sterilization |
| Answer» B. Incineration | |
| 158. |
Microorganisms are commonly known as |
| A. | germs only |
| B. | microbes only |
| C. | gametes |
| D. | germs and microbes |
| Answer» E. | |
| 159. |
For using any chemical agent, we need to increase the temperature of the environment. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 160. |
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» E. | |
| 161. |
Which of the following organelles contain DNA, divides and possesses some degree of autonomy? |
| A. | Golgi apparatus |
| B. | Ribosome |
| C. | Chloroplast |
| D. | Peroxisomes |
| Answer» D. Peroxisomes | |
| 162. |
Which of the following instruments is used to perform tyndallization? |
| A. | Autoclave |
| B. | Steam Arnold |
| C. | Gas oven |
| D. | Incubator |
| Answer» C. Gas oven | |
| 163. |
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» E. | |
| 164. |
Which of the following was the first widely used antiseptic and disinfectant? |
| A. | Chlorine |
| B. | Phenol |
| C. | Iodine |
| D. | Alcohol |
| Answer» C. Iodine | |
| 165. |
Which of the following is the characteristics of a sanitizer? |
| A. | destroys all microbial forms |
| B. | prevents the growth or action of microorganisms |
| C. | reduces the microbial population to safe levels |
| D. | kills all the bacteria and the bacterial spores |
| Answer» D. kills all the bacteria and the bacterial spores | |
| 166. |
Oil immersion objective lens has an NA value of____________ |
| A. | 0.65 |
| B. | 0.85 |
| C. | 1.33 |
| D. | 1.00 |
| Answer» D. 1.00 | |
| 167. |
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» D. Magnifying lens | |
| 168. |
What is the minimum distance for the eye to focus any object? |
| A. | 11 cm |
| B. | 25 cm |
| C. | 32 cm |
| D. | 4 2 cm |
| Answer» C. 32 cm | |
| 169. |
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» E. | |
| 170. |
On what factors do the intensity of secondary electrons depends upon? |
| A. | shape of the irradiated object |
| B. | chemical composition of the irradiated object |
| C. | number of electrons ejected |
| D. | size and chemical composition of the irradiated object, number of electrons ejected and on the number of electrons reabsorbed by surrounding |
| Answer» E. | |
| 171. |
The secondary electrons radiated back in scanning microscope is collected by? |
| A. | specimen |
| B. | anode |
| C. | vacuum chamber |
| D. | cathode |
| Answer» C. vacuum chamber | |
| 172. |
Where do we obtain the magnified image of the specimen in SEM? |
| A. | cathode ray tube |
| B. | phosphorescent screen |
| C. | anode |
| D. | scanning generator |
| Answer» B. phosphorescent screen | |
| 173. |
Motile-bacterium moves with the help of a |
| A. | whip |
| B. | tail |
| C. | flagellum |
| D. | wings |
| Answer» D. wings | |
| 174. |
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» E. | |
| 175. |
Wavelengths around ___________ have the highest bactericidal efficiency. |
| A. | 150 Å |
| B. | 3900 Å |
| C. | 2650 Å |
| D. | 500 Å |
| Answer» D. 500 Å | |
| 176. |
Which of the following apparatus is used to provide steam under regulated pressure? |
| A. | autoclave |
| B. | laminar air flow |
| C. | incubator |
| D. | hot oven |
| Answer» B. laminar air flow | |
| 177. |
We observe increased growth in nutrient agar plates as concentration of chemical agent is decreased. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» B. False | |
| 178. |
Which of the following chemical agents lack penetrating power? |
| A. | Phenol |
| B. | Iodine |
| C. | Ethylene oxide |
| D. | Beta-propiolactone |
| Answer» E. | |
| 179. |
Which of the following is best used for long term storage of microbial samples when carried out properly? |
| A. | Storage in a freezer at -10°C |
| B. | Storage in a freezer at ultra low temperatures (-70°C) |
| C. | Storage in a refrigerator on an agar slant |
| D. | Storage on a petri plate at room temperature |
| Answer» C. Storage in a refrigerator on an agar slant | |
| 180. |
The general pressure at which the autoclave is operated is ___________ |
| A. | 5 Psi |
| B. | 20 Psi |
| C. | 15 Psi |
| D. | 40 Psi |
| Answer» D. 40 Psi | |
| 181. |
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» C. Compound Microscope | |
| 182. |
% Similarity (%S) of each strain to every other strain is calculated by which method? |
| A. | Intuitive Method |
| B. | Numerical Taxonomy |
| C. | Genetic Relatedness |
| D. | DNA homology experiments |
| Answer» C. Genetic Relatedness | |
| 183. |
The process of killing all microorganisms along with their spores is ____________________ |
| A. | Disinfection |
| B. | Antisepsis |
| C. | Sanitization |
| D. | Sterilization |
| Answer» E. | |
| 184. |
Mycoplasmas, rickettsiae, and chlamydiae are |
| A. | types of fungi |
| B. | small bacteria |
| C. | species of protozoa |
| D. | forms of viruses |
| Answer» C. species of protozoa | |
| 185. |
Which of the following radiations have the energy to knock electrons away from molecules and ionize them? |
| A. | Non-ionizing radiations |
| B. | Acoustic radiations |
| C. | Subatomic particles |
| D. | Ionizing radiations |
| Answer» E. | |
| 186. |
The time in minutes at a specific temperature needed to kill a population of cells is the |
| A. | decimal reduction time |
| B. | thermal death point |
| C. | thermal death temperature |
| D. | F value |
| Answer» E. | |
| 187. |
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» C. Crystal violet, safranin, alcohol, iodine solution | |
| 188. |
A characteristic of protein synthesis in both the archaea and eukarya is |
| A. | transcription and translation are coupled |
| B. | translation is inhibited by diphtheria toxin |
| C. | proteins are synthesized from D-, rather than L-, isomers of amino acids |
| D. | the initiator tRNA is charged with N-formyl-methionine |
| Answer» D. the initiator tRNA is charged with N-formyl-methionine | |
| 189. |
Which disinfectant would be most effective against Staphylococcus found in a blood spill? |
| A. | Phenol |
| B. | Cetylpyridinium chloride |
| C. | Hexachlorophene |
| D. | None of these |
| Answer» E. | |
| 190. |
Which of the following structure is present in prokaryotic cells? |
| A. | Mitochondria |
| B. | Chloroplasts |
| C. | Golgi structure |
| D. | Mesosome |
| Answer» E. | |
| 191. |
Which of the following is not found in the kingdom Monera? |
| A. | Organelles |
| B. | Organized cell structure |
| C. | Ability to reproduce |
| D. | Ability to use energy |
| Answer» B. Organized cell structure | |
| 192. |
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» E. | |
| 193. |
Negative Staining is used for examining _____________ |
| A. | virus particles |
| B. | protein molecules |
| C. | bacterial flagella |
| D. | virus particles, protein molecules and bacterial flagella |
| Answer» E. | |
| 194. |
Electron Microscope can give a magnification up to ___________ |
| A. | 400,000X |
| B. | 100,000X |
| C. | 15000X |
| D. | 100X |
| Answer» B. 100,000X | |
| 195. |
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» E. | |
| 196. |
Degree of scattering in transmission electron microscope is a function of __________ |
| A. | wavelength of electron beam used |
| B. | number of atoms that lie in the electron path |
| C. | number and mass of atoms that lie in the electron path |
| D. | mass of atoms that lie in the electron path |
| Answer» D. mass of atoms that lie in the electron path | |
| 197. |
Iodophores are mixture of |
| A. | iodine and aldehydes |
| B. | iodine and surface active agents |
| C. | iodine and alcohols |
| D. | iodine and phenols |
| Answer» C. iodine and alcohols | |
| 198. |
For sterilization of plastic syringes in hospitals which of the following agents are used? |
| A. | ethylene oxide |
| B. | dyes |
| C. | radiations |
| D. | heavy metals |
| Answer» B. dyes | |
| 199. |
Ethylene oxide is used to destroy or kill which of the following microbes? |
| A. | Bacteria |
| B. | Spores |
| C. | Fungi |
| D. | All of these |
| Answer» E. | |
| 200. |
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» D. temperature conditions are different | |