MCQOPTIONS
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MCQOPTIONS
This section includes 105 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
species from human oral cavity can be selected by using |
| A. | pH of the medium |
| B. | incubation temperature |
| C. | cell size and motility |
| D. | all of these |
| Answer» D. all of these | |
| 2. |
To select cholera-causing bacterium, , the pH of the medium is maintained at a pH of |
| A. | 8.5 |
| B. | 8.90 |
| C. | 6.79 |
| D. | 3.5 |
| Answer» B. 8.90 | |
| 3. |
Which of the following chemotherapeutic agents may affect the growth of ? |
| A. | Vacomycin |
| B. | Polymyxin |
| C. | Trimethoprim |
| D. | None of these |
| Answer» E. | |
| 4. |
forms a blue water soluble pigment called |
| A. | pyocyanin |
| B. | chlororaphin |
| C. | pyoverdin |
| D. | β-carotene |
| Answer» B. chlororaphin | |
| 5. |
Which of the following problem makes it impossible to satisfy all of Koch's postulates? |
| A. | Microorganism causes serious symptoms in humans |
| B. | Microorganism cannot be isolated in pure culture |
| C. | Species of microorganism is in question |
| D. | Genes from the microorganism cannot be amplified by PCR |
| Answer» C. Species of microorganism is in question | |
| 6. |
Stuart's transport medium is used for transport of specimen containing |
| A. | Neisseria gonorrhoeae |
| B. | Salmonella |
| C. | Vibrio cholerae |
| D. | Shigella |
| Answer» B. Salmonella | |
| 7. |
Intestinal bacteria can grow in the presence of __________ whereas nonintestinal bacteria are usually inhibited. |
| A. | bile salts |
| B. | low concentration of various dyes |
| C. | sugars |
| D. | low levels of nitrogen |
| Answer» B. low concentration of various dyes | |
| 8. |
Which of the following methods is most likely to be quantitative? |
| A. | Dilution and plating |
| B. | Gram staining |
| C. | Wet mount |
| D. | None of these |
| Answer» B. Gram staining | |
| 9. |
Cell counting can be carried out by |
| A. | direct microscopic count using petroffhansser counting chamber |
| B. | plate counting |
| C. | membrane filter count |
| D. | all of the above |
| Answer» E. | |
| 10. |
Intracellular enzymes |
| A. | synthesize cellular material only |
| B. | synthesize cellular material and perform catabolic reaction |
| C. | synthesize cellular material and perform anabolic reaction |
| D. | only provide energy to the cell |
| Answer» C. synthesize cellular material and perform anabolic reaction | |
| 11. |
Enzymes can |
| A. | not pass through semipermeable membrane |
| B. | pass through semipermeable membrane |
| C. | dissolve semipermeable membrane |
| D. | none of these |
| Answer» B. pass through semipermeable membrane | |
| 12. |
Balanced growth is defined as |
| A. | cultures undergoing balanced growth while maintaining a constant chemical composition |
| B. | balancing the growth while controlling the pH |
| C. | balancing the growth while controlling the temperature |
| D. | balancing the growth while changing the nutrient composition |
| Answer» B. balancing the growth while controlling the pH | |
| 13. |
Who coined the word enzyme first? |
| A. | Kuhne |
| B. | Pasteur |
| C. | Liebig |
| D. | Buchner |
| Answer» B. Pasteur | |
| 14. |
Isozymes or iso enzymes are those enzyme which |
| A. | have same structural forms |
| B. | have different structural forms but identical catalytic properties |
| C. | catalyses oxidation reactions |
| D. | none of these |
| Answer» C. catalyses oxidation reactions | |
| 15. |
When a substance is added to a solid medium which inhibits the growth of unwanted bacteria but permits the growth of wanted bacteria, it is known as |
| A. | differential medium |
| B. | enriched medium |
| C. | enrichment medium |
| D. | selective medium |
| Answer» E. | |
| 16. |
Peptone water and nutrient broth are |
| A. | selective media |
| B. | enriched media |
| C. | basal media |
| D. | none of these |
| Answer» D. none of these | |
| 17. |
When a substance is added to a liquid medium which inhibits the growth of unwanted bacteria and favors the growth of wanted bacteria, it is known as |
| A. | differential medium |
| B. | enriched medium |
| C. | enrichment medium |
| D. | selective medium |
| Answer» D. selective medium | |
| 18. |
Enzyme catalase has non-protein metal as |
| A. | magnesium |
| B. | manganese |
| C. | iron |
| D. | zinc |
| Answer» D. zinc | |
| 19. |
Semi-solid media, prepared with agar at concentrations of 0.5% or less are useful for the cultivation of |
| A. | Microaerophillic bacteria |
| B. | Lactobacilli |
| C. | E.coli |
| D. | all of these |
| Answer» B. Lactobacilli | |
| 20. |
A medium containing crystal violet dye plus sodium deoxycholate will allow |
| A. | gram (-)ve intestinal bacteria to grow |
| B. | gram (+)ve intestinal bacteria to grow |
| C. | aquatic bacteria to grow |
| D. | none of these |
| Answer» B. gram (+)ve intestinal bacteria to grow | |
| 21. |
The medium which allows the growth of more than one microorganisms of interest but with morphologically distinguishable colonies is known as |
| A. | selective medium |
| B. | enrichment medium |
| C. | differential medium |
| D. | none of these |
| Answer» D. none of these | |
| 22. |
The cell mass can be measured optically by determining the amount of light scattered by a suspension of cells. The measurements are usually at a wavelength of |
| A. | 300-400nm |
| B. | 400-500nm |
| C. | 500-600nm |
| D. | 600-700nm |
| Answer» E. | |
| 23. |
Viable plate count can be obtained using |
| A. | Spread plate method |
| B. | Pour plate method |
| C. | both (a) and (b) |
| D. | Hemocytometer |
| Answer» D. Hemocytometer | |
| 24. |
For most bacteria, the optimum pH for growth lies between |
| A. | 6.5-7.5 |
| B. | 3.5-4.5 |
| C. | 4.5-5.5 |
| D. | 5.5-6.5 |
| Answer» B. 3.5-4.5 | |
| 25. |
The size of a single plant cell is usually within the range of |
| A. | 10-20μm in diameter and 25-100μm long |
| B. | 20-40μm in diameter and 100-200μm long |
| C. | 40-60μm in diameter and 200-300μm long |
| D. | 60-80μm in diameter and 300-400μm long |
| Answer» C. 40-60μm in diameter and 200-300μm long | |
| 26. |
Which of the following hint(s) suggest/s that a given specimen is likely to contain anaerobic bacteria? |
| A. | Gas in specimen |
| B. | Foul odour |
| C. | Presence of sulphur granules |
| D. | All of these |
| Answer» E. | |
| 27. |
The archaebacterium Halobacterium, an extreme halophile, and Sulfolobus, a thermoacidophile, can be cultured in the presence of antibiotics such as streptomycin and chloramphenicol because |
| A. | they contain ether-linked isoprenoids in their plasma membrane |
| B. | they lack murein in their cell wall |
| C. | they contain 80S, as opposed to 70S, ribosomes |
| D. | all of the above |
| Answer» C. they contain 80S, as opposed to 70S, ribosomes | |
| 28. |
Thiobacillus thiooxidans has an optimum pH of |
| A. | 2.0-3.5 |
| B. | 0.5-6.0 |
| C. | 6.5-7.5 |
| D. | 9.0-9.5 |
| Answer» B. 0.5-6.0 | |
| 29. |
Allosteric enzymes are |
| A. | larger than simple enzyme |
| B. | smaller than simple enzyme |
| C. | larger and more complex than simple enzyme |
| D. | smaller than simple enzyme but not complex |
| Answer» D. smaller than simple enzyme but not complex | |
| 30. |
Callus cultures are amorphous cell aggregates arising from the unorganized growth of explants on an |
| A. | liquid medium |
| B. | solid nutrient medium |
| C. | aseptic solid nutrient medium |
| D. | solid or liquid medium |
| Answer» D. solid or liquid medium | |
| 31. |
Protein portion of an enzyme when it is combined with organic molecule is termed as |
| A. | apoenzyme |
| B. | co-enzyme |
| C. | holoenzyme |
| D. | co-factors |
| Answer» B. co-enzyme | |
| 32. |
Suspension cultures consist of cells and cell aggregates, growing dispersed in |
| A. | liquid medium |
| B. | solid nutrient medium |
| C. | solid or liquid medium |
| D. | none of these |
| Answer» B. solid nutrient medium | |
| 33. |
The isolation of the gonorrhoea - causing organisms, Neisseria gonorrhoeae,from a clinical specimen is facilitated by the use of media containing |
| A. | cellulose |
| B. | certain antibiotics |
| C. | succinate |
| D. | none of these |
| Answer» C. succinate | |
| 34. |
Which of the following is not an indirect method for the measurement of cell mass? |
| A. | Nutrient composition |
| B. | Cell dry weight |
| C. | Viscosity |
| D. | Heat evolution |
| Answer» C. Viscosity | |
| 35. |
The inactive protein from of enzyme is |
| A. | apoenzyme |
| B. | enzyme |
| C. | haloenzyme |
| D. | cofactor |
| Answer» B. enzyme | |
| 36. |
Selective media facilitate growth of only one kind of organism. Saboraud medium is used to selectively isolate |
| A. | coliform bacteria |
| B. | gram positive bacteria |
| C. | yeasts |
| D. | acid fast organisms |
| Answer» D. acid fast organisms | |
| 37. |
Anchorage -dependent cells require |
| A. | wettable surface for growth |
| B. | dry surface for growth |
| C. | either (a) or (b) |
| D. | nothing to do with the surface |
| Answer» B. dry surface for growth | |
| 38. |
Which of the following techniques may be performed quantitatively to determine the number of bacteria of a particular type? |
| A. | Pour plate |
| B. | Spread plate |
| C. | Both (a) and (b) |
| D. | Streak plate technique |
| Answer» D. Streak plate technique | |
| 39. |
Treponema species from human oral cavity can be selected by using |
| A. | pH of the medium |
| B. | incubation temperature |
| C. | cell size and motility |
| D. | all of these |
| Answer» D. all of these | |
| 40. |
Enzymes are |
| A. | organic compounds produced by living organism |
| B. | inorganic compounds |
| C. | organic as well as inorganic compounds |
| D. | all of these |
| Answer» B. inorganic compounds | |
| 41. |
Plate counts are often reported as |
| A. | cfu |
| B. | cfu/ml |
| C. | Both (a) and (b) |
| D. | thousands/ml |
| Answer» C. Both (a) and (b) | |
| 42. |
All bacteria that inhabit the human body are |
| A. | heterotrophs |
| B. | chemolithotrophs |
| C. | autotrophs |
| D. | phototroph |
| Answer» B. chemolithotrophs | |
| 43. |
Which of the following is the necessary step for cultivating the microorganisms? |
| A. | Preparing a culture medium for the growth of microorganisms |
| B. | Sterilizing in order to eliminate all living microorganisms in vessel |
| C. | Inoculating the microorganisms in the prepared medium |
| D. | All of the above |
| Answer» E. | |
| 44. |
Disease-producing species occurring in a mixed culture can be selected by taking advantage of _________ |
| A. | its pathogenic properties |
| B. | special carbon source |
| C. | special nitrogen source |
| D. | toxic chemicals |
| Answer» B. special carbon source | |
| 45. |
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» D. 0 degree C | |
| 46. |
Treponema sp. can be selected by taking advantage of ____________ |
| A. | small cell size |
| B. | motility |
| C. | dilute media |
| D. | small cell diameter and bacterial motility |
| Answer» E. | |
| 47. |
Roll-tube technique is used to isolate ___________ |
| A. | aerobes |
| B. | anaerobes |
| C. | facultatives |
| D. | stringent anaerobes |
| Answer» E. | |
| 48. |
Vibrio cholerae can grow in a medium with a pH of _______ |
| A. | 5.5 |
| B. | 7.0 |
| C. | 8.5 |
| D. | 2.0 |
| Answer» D. 2.0 | |
| 49. |
Enrichment media allows the growth of a large number of varied bacterial species. |
| A. | True |
| B. | False |
| C. | May be |
| D. | Can't say |
| Answer» C. May be | |
| 50. |
In physical method of selection, endospore-forming bacteria can be obtained by heating the mixed culture to _____________ |
| A. | 70 degree C for 10 minutes |
| B. | 80 degree C for 10 minutes |
| C. | 60 degree C for 10 minutes |
| D. | 90 degree C for 10 minutes |
| Answer» C. 60 degree C for 10 minutes | |