MCQOPTIONS
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MCQOPTIONS
This section includes 172 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Water activity can act as |
| A. | an intrinsic factor determining the likelihood of microbial proliferation |
| B. | a processing factor |
| C. | an extrinsic factor |
| D. | all of the above |
| Answer» E. | |
| 2. |
Which of the following is true about ISO 2002 method for Salmonella detection? |
| A. | Selenite cystine (SC) broth is replaced by Muller Kauffmann tetrathionate novobiocin broth (MKTTn) |
| B. | Rappaport Vassiliadis (RV) broth has been replaced by Rappaport Vassiliadis Soya (RVS) broth |
| C. | XLD is the first isolation medium rather than BGA |
| D. | All of these |
| Answer» E. | |
| 3. |
Salmonellois is caused by the |
| A. | enterotoxin of Salmonella spp |
| B. | endotoxin of Salmonella spp |
| C. | neurotoxin of Salmonella spp |
| D. | exoenterotoxin of Salmonella spp |
| Answer» C. neurotoxin of Salmonella spp | |
| 4. |
A dense bacterial population caught in a tangled web of fibers sticking to a surface describes |
| A. | coagulation |
| B. | a biodisc |
| C. | a biofilm |
| D. | the membrane filter technique |
| Answer» D. the membrane filter technique | |
| 5. |
Which statement is true about flavouring materials spices, garlic etc. added to Dill pickles? |
| A. | These markedly stimulate or inhibit the acid forming bacteria |
| B. | They may be source of considerable numbers of undesirable micro-organisms and cause off-fermentations or spoilage of pickles |
| C. | They may improve texture of the pickle |
| D. | None of these |
| Answer» C. They may improve texture of the pickle | |
| 6. |
A psychrophilic halophile would be a microbe that prefers |
| A. | cold temperatures and increased amounts of salt |
| B. | warm temperatures and increased amounts of pressure |
| C. | cold temperatures and the absence of oxygen |
| D. | warm temperatures and increased amounts of acid |
| Answer» B. warm temperatures and increased amounts of pressure | |
| 7. |
The death of a river by environmental pollutants ultimately results from |
| A. | the overpopulation of algae |
| B. | the overabundance of toxic proteins |
| C. | the depletion of oxygen |
| D. | the buildup of sediment on the river bottom |
| Answer» D. the buildup of sediment on the river bottom | |
| 8. |
Which of the following statement is not correct? |
| A. | The use of 25-40°C temperatures allows the biogas production to be more stable |
| B. | The use of 25-40°C temperatures does not destroy potentially harmful bacteria |
| C. | The use of 25-40°C temperatures destroys potentially harmful bacteria |
| D. | None of the above |
| Answer» D. None of the above | |
| 9. |
Botulism is caused by the presence of toxin developed by |
| A. | Clostridium tyrobutyricum |
| B. | Clostridium sporogenes |
| C. | Clostridium botulinum |
| D. | none of these |
| Answer» D. none of these | |
| 10. |
Which of the following is not employed as an oxidation method? |
| A. | Oxidation ponds |
| B. | Trickling filters |
| C. | Contact aerators |
| D. | All of these |
| Answer» E. | |
| 11. |
Which of the following acid will have higher bacteriostatic effect at a given pH? |
| A. | Acetic acid |
| B. | Tartaric acid |
| C. | Citric acid |
| D. | Maleic acid |
| Answer» B. Tartaric acid | |
| 12. |
Ropiness in bread is caused by |
| A. | Bacillus subtilis |
| B. | A. niger |
| C. | R. nigricans |
| D. | P. expansum |
| Answer» B. A. niger | |
| 13. |
A special beer yeast of the bottom type is |
| A. | S. cerevisiae |
| B. | S. carlsbergensis |
| C. | S. thermophillus |
| D. | none of these |
| Answer» C. S. thermophillus | |
| 14. |
The potential spoilage organism in beer is |
| A. | Saccharomyces diastaticus |
| B. | S. carlsbergensis |
| C. | S. cerevisiae |
| D. | S. lactis |
| Answer» B. S. carlsbergensis | |
| 15. |
The use of microbes to break down synthetic waste products such as polychlorinated biphenyls is called |
| A. | bioinformatics |
| B. | biolistics |
| C. | biotechnology |
| D. | bioremediation |
| Answer» E. | |
| 16. |
The concept of putting microbes to help clean up the environment is called |
| A. | pasteurization |
| B. | bioremediation |
| C. | fermentation |
| D. | biolistics |
| Answer» C. fermentation | |
| 17. |
The different ACC's between food categories reflect the |
| A. | expected level of contamination of the raw material |
| B. | potential for microbial growth during storage |
| C. | potential shelf life |
| D. | all of the above |
| Answer» E. | |
| 18. |
Arrange the potencies of toxin in descending order of the following canned foods |
| A. | peas>string beans>spinach> corn |
| B. | corn> string bean>peas>spinach |
| C. | corn> spinach> peas>string beans |
| D. | corn> peas>string beans>spinach |
| Answer» E. | |
| 19. |
The crushed grapes used for wine manufacturing are also known as |
| A. | wort |
| B. | must |
| C. | hop |
| D. | pilsener |
| Answer» C. hop | |
| 20. |
The biogas production process takes place at the temperature |
| A. | lesser than 25°C |
| B. | 25-40°C |
| C. | 45-60°C |
| D. | all of these |
| Answer» E. | |
| 21. |
The most important bacterium developing acidity in both low and high salt brines is |
| A. | L. lactis |
| B. | L. plantarum |
| C. | L. brevis |
| D. | B. subtilis |
| Answer» C. L. brevis | |
| 22. |
A bacterial food intoxication refers to |
| A. | illness caused by presence of pathogens |
| B. | food borne illness caused by the presence of a bacterial toxin formed in food |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» C. both (a) and (b) | |
| 23. |
The microbiological examination of coliform bacteria in foods preferably use |
| A. | MacConkey broth |
| B. | violet Red Bile agar |
| C. | eosine Methylene blue agar |
| D. | all of these |
| Answer» E. | |
| 24. |
Gassiness resulting from the liberation of carbon dioxide by hetero fermentative lactics is called |
| A. | pousse |
| B. | amertume |
| C. | mannitic |
| D. | none of these |
| Answer» B. amertume | |
| 25. |
What is an anaerobic digester? |
| A. | New diet drink |
| B. | Microbe that eats hazardous waste |
| C. | Method to convert agricultural waste into a biogas |
| D. | All of the above |
| Answer» D. All of the above | |
| 26. |
The acetate-utilizing methanogens are responsible for |
| A. | 20% of methane produced in a biogas reactor |
| B. | 50% of methane produced in a biogas reactor |
| C. | 70% of methane produced in a biogas reactor |
| D. | 85% of methane produced in a biogas reactor |
| Answer» D. 85% of methane produced in a biogas reactor | |
| 27. |
Water testing relies on the detection of certain indicator organisms known as |
| A. | acid-fast bacteria |
| B. | bacteroids |
| C. | coliforms |
| D. | dinoflagellates |
| Answer» D. dinoflagellates | |
| 28. |
Grains spoiled by molds are a potential animal or human health hazard as well as a great economic loss. Which is/are the common species of molds in the spoilage of stored grains by molds? |
| A. | Aspergillus |
| B. | Penicillium |
| C. | Fusarium |
| D. | All of these |
| Answer» E. | |
| 29. |
Sulfur stinker spoilage, caused by is uncommonly found in |
| A. | low acid foods |
| B. | medium acid foods |
| C. | high acid foods |
| D. | any of these |
| Answer» B. medium acid foods | |
| 30. |
An excessively high temperature in the fermentation of sauerkraut may inhibit the growth of |
| A. | Leuconostoc |
| B. | Pediococcus cerevisiae |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» B. Pediococcus cerevisiae | |
| 31. |
What are the intrinsic factors for the microbial growth? |
| A. | pH |
| B. | Moisture |
| C. | Oxidation-Reduction Potential |
| D. | All of these |
| Answer» E. | |
| 32. |
Flat sour spoilage of acid foods is caused by |
| A. | B. coagulans |
| B. | B. pepo |
| C. | both (a) and (b) |
| D. | B. stearothermophillus |
| Answer» B. B. pepo | |
| 33. |
The presence of viable non-spore forming bacteria in heat process canned foods indicates leakage of the container. Which of the following is responsible for the spoilage of leaky cans? |
| A. | Plant equipment |
| B. | Cooling water |
| C. | Highly acidic medium |
| D. | High sugar content |
| Answer» C. Highly acidic medium | |
| 34. |
Activated sludge contains large number of |
| A. | bacteria |
| B. | yeasts and molds |
| C. | protozoa |
| D. | all of these |
| Answer» E. | |
| 35. |
The Sarcina sickness of beer, caused by Pedicoccus cerevisiae, is characterized by |
| A. | sourness |
| B. | turbidity |
| C. | popiness |
| D. | all of these |
| Answer» E. | |
| 36. |
Slippery pickles occur due to |
| A. | growth of encapsulated bacteria |
| B. | broken scums of film yeasts on the surface of brine |
| C. | addition of high amount of salt |
| D. | both (a) and (b) |
| Answer» E. | |
| 37. |
The favouring conditions for floaters is |
| A. | high intial amounts of salt |
| B. | thick skin that does not allow gas to diffuse out |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» D. none of these | |
| 38. |
Blackening in pickles occurs due to |
| A. | the formation of hydrogen sulfide by bacteria |
| B. | growth of Pencillium |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. growth of Pencillium | |
| 39. |
Mined salt has been reported to contain about |
| A. | 50% Micrococcus, 10% Coryneforms and 14% Bacillus |
| B. | 60% Micrococcus, 20% Coryneforms and 14% Bacillus |
| C. | 70% Micrococcus, 20% Coryneforms and 4% Bacillus |
| D. | 70% Micrococcus, 20% Coryneforms and 10% Bacillus |
| Answer» D. 70% Micrococcus, 20% Coryneforms and 10% Bacillus | |
| 40. |
Most important species of vinegar bacteria causing sliminess is |
| A. | Acetobacter aceti |
| B. | Saccharomyces carlsbergiensis |
| C. | Lactobacillus lactis |
| D. | None of the above |
| Answer» B. Saccharomyces carlsbergiensis | |
| 41. |
Which of the following strain(s), that grow in the jellies and candid fruits, are able to grow in sugar concentration upto 67.5%? |
| A. | Aspergillus |
| B. | Penicillium |
| C. | Citromyces |
| D. | All of these |
| Answer» E. | |
| 42. |
High acid foods with a pH < 3.7 undergo spoilage by |
| A. | Saccharolytic anaerobe |
| B. | B. coagulans |
| C. | both (a) and (b) |
| D. | do not undergo spoilage by microorganisms |
| Answer» E. | |
| 43. |
Shriveling in fermented pickles results from the physical effect of |
| A. | too strong salt solution |
| B. | too strong sugar solution |
| C. | too strong vinegar solution |
| D. | all of these |
| Answer» E. | |
| 44. |
Yeast and mould count determination requires- |
| A. | nutrient agar |
| B. | acidified potato glucose agar |
| C. | MacConkey agar |
| D. | violet Red Bile agar |
| Answer» C. MacConkey agar | |
| 45. |
Some cyanobacteria produce potent neurotoxins that, if ingested, will kill humans. These cyanobacteria are most likely to contaminate |
| A. | water rich in organic carbon wastes but poor in phosphate |
| B. | water that are anoxic |
| C. | water rich in phosphate wastes but poor in organic carbon |
| D. | none of the above |
| Answer» D. none of the above | |
| 46. |
The elimination of the scum of yeasts in the brine during the fermentation include |
| A. | agitation of the surface |
| B. | addition of the mustard oil |
| C. | addition of the sorbic acid |
| D. | all of these |
| Answer» E. | |
| 47. |
Which of the following species can cause bitterness, acidity and curdling in canned milk, cream and evaporated milk? |
| A. | Bacillus |
| B. | Clostridium |
| C. | both (a) and (b) |
| D. | Saccharomyces |
| Answer» B. Clostridium | |
| 48. |
When the fermentation of fructose results in the bitter product mannitol, the fermentation is sometime termed as- |
| A. | mannkic |
| B. | mannitic |
| C. | amertume |
| D. | none of these |
| Answer» C. amertume | |
| 49. |
Parsnip like odour and taste in beer is caused by |
| A. | Flavobacterium proteus |
| B. | Zygomonas anaeroium |
| C. | Lactobacillus patorianus |
| D. | S. carlsbergensis |
| Answer» B. Zygomonas anaeroium | |
| 50. |
Acetic acid bacteria spoiling musts and wines are inhibited by |
| A. | 5-7% alcohol by volume |
| B. | 14-15% alcohol by volume |
| C. | 24-25% alcohol by volume |
| D. | 30-35% alcohol by volume |
| Answer» C. 24-25% alcohol by volume | |