FOOD MICROBIOLOGY MCQs | Food Preservation | Food Technology

In this post, we are going to cover FOOD MICROBIOLOGY MCQs | Food Preservation | Food Technology topics. firstly discuss important information of food microbiology after that Quiz section.


Food Microbiology and Safety

Food microbiology places a lot of emphasis on food safety. Food can easily spread several pathogens and disease-causing agents, including viruses and bacteria. Food may also be contaminated by microbial toxins; however, microorganisms and their byproducts can also be employed to fight off these harmful germs. Food microbiology and safety practices are as follows:

  • Consider every microorganism to be a potential pathogen.
  • Keep an organised collection of cultural items
  • Each year, obtain fresh stock cultures of microorganisms.
  • Clean and sanitise the tools and supplies
  • Clean up work surfaces both before and after each use.
  • Wear safety suits
  • Clean your hands
  • Never use a mouth pipette
  • Avoid taking food or beverages into the lab or storing them in locations where microbes are kept.
  • Clearly label everything
  • Disinfect or autoclave all waste
  • Clean up spills carefully

Food Micro Lab

Food spoilage, sickness, growth, and fermentation are all caused by microbes, which are studied in food micro labs. The procedure of studying these microorganisms is delicate and calls for specific environmental conditions and exacting hygiene in order to yield reliable data.

Food Microbiology Lab

Food microbiology lab is one of the essential places for microbiologists to do their essential researches. And they have a range of equipment present in the food microbiology lab which discussed as follows:

  • Autoclave
  • Analytical Balance
  • Colony Counter
  • Hot Plate
  • Hot Air Oven
  • Incubators
  • Laminar Flow Hood
  • Microscope
  • Magnetic Stirrer
  • pH Meter
  • Water Bath
  • Spectrophotometer
  • Water Distiller

Food Microbiology Laboratory

A food microbiology laboratory is one that specialises in growing, examining, and identifying microorganisms including bacteria, yeasts, fungus, etc. The microbiology lab is essential for efficient infection control and prevention (IPC).

Food Safety Microbiology

Food safety microbiology is essential for performing the right techniques for identify the food microbes. The techniques of food safety microbiology are as follows:

  • Sterilization
  • Disinfection
  • Sanitization
  • Culture Techniques
  • Inoculation and Incubation
  • Enumerating Bacteria
  • Identification of Pathogen


1. Who laid the foundation for a scientific approach to the classification of microorganisms?

a. Aristotle

b. Lehmann and Niemann

c. Leeuwenhoek

d. Lederberg and Tautom

Ans. b

2. A clearly defined polysaccharides layer surrounding the cell of certain prokaryotes is called:

a. Flagella

b. Capsule

c. Plasmid

d. Mesosome

Ans. b

3. Gram staining was discovered by:

a. Christian Gram

b. Henry Gram

c. Phillip Gram

d. Thomas Gram

Ans. a

4. The composition of capsule of bacteria is:

a. Fatty acids

b. Polysaccharides

c. Polypeptides

d. All of the above

Ans. b

5. Which of the following statements is/are correct?

a. Streptococcus pneumoniae can not form capsule when it is inside the human body

b. Capsules can not be seen under microscope

c. Bacterial capsules are species specific

d. All of the above

Ans. c

6. Which of the following statements is/are correct?

a. Mesosomes are more frequent in gram -ve bacteria

b. In gram +ve bacteria, the outer membrane of the cell envelope is absent

c. Pilli may be present in prokaryotic cells

d. All of the above

Ans. d

7. Which of the following is/are storage granules in bacteria?

a. Polymetaphosphate

b. Poly a-hydroxy butyrate granules

c. Polyglucan granules

d. All of the above

Ans. d

MCQs on Food Preservation |Food Technology Multiple Choice Questions and Answers pdf

8. The capsule of pseudomonas aeruginosa is composed of:

a. heteropolysaccharides

b. homopolysaccharides

c. phospholipids

d. pectin

Ans. a

9. Which model is used to explain the cell structure of bacteria?

a. Fluid mosaic model

b. Pumpkin model

c. Pasteur model

d. None

Ans. a

10. Major chemical compound present in the endospore of bacteria is:

a. calcium tenate

b. calcium pectate

c. calcium picolinate

d. All of the above

Ans. c

Microbial testing in food | Microbiology in food industry

11. Which mycelium of the Actinomycetes is hydrophobic in nature?

a. Aerial

b. Substrate

c. Both a and b

d. Neither a nor b

Ans. a

12. Which mycelium of the Actinomycetes is hydrophillic in nature?

a. Aerial

b. Substrate

c. Both a and b

d. Neither a nor b

Ans. b

13. The counter stain used in Gram staining is:

a. Safranin

b. Crystal violet

c. Water

d. Ethanol

Ans. a

14. The non motile fungal spores are known as:

a. Aplanospores

b. Pianospores

c. Zygospores

d. Hypnospores

Ans. a


15. The female gamentangium of fungi is known as:

a. Antheridium

b. Oogonium

c. Zygote

d. Conidia

Ans. b

16. Which of the following staining method is the best study shape of microbes?

a. Gram staining

b. Acid fast staining

c. Negative staining

d. All of the abovve

Ans. b

17. The color of spores in Wirtz method is:

a. Red

b. Green

c. Pink

d. Blue

Ans. b

18. The color of spore in Dorner’s method?

a. Black

b. White

c. Red

d. Yellow

Ans. d

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19. Method most suitable for sterilizing blood serum is;

a. Arnold method

b. Chemical method

c. Autoclave

d. Filteration

Ans. d

20. Which of the following methods of flagella staining uses silver nitrate as a staining agent?

a. West method

b. ray method

c. Arnold method

d. None of the above

Ans. a

21. Wirtz-Conklin method is used for:

a. cell wall staining

b. Flagella stainin

c. Endospore staining

d. Capsule staining

Ans. c

General Microbiology Multiple Choice Questions

22. Mordant used in staining of flagella:

a. Ethyl chloride

b. Tannic acid

c. Cetyl pyrimidine chloride

d. Potassium picolinate

Ans. b

23. Decolorizer used in gram staining is:

a. Water

b. Alcohol

c. Benzene

d. Any of the above

Ans. b

24. The decolorizer used in capsule staining is:

a. Cetyl pyrimidine chloride

b. Copper sulphate

c. Alcohol

d. Benzene hexachloride

Ans. b

25. Which staining technique is best suited to know the shape of microorganisms ?

a. Positive staining

b. Negative staining

c. Fluorescent staining

d. Acid fast staining

Ans. b

26. Which staining technique is best suited to know the presence of mycobacterium species in culture?

a. Positive staining

b. Negative stainingg

c. Fluorescent stainin

d. Acid fast stainin

Ans. d

27. The decolorizer used in case of flagella staining is:

a. Water

b. Alcohol

c. Calcium hydroxide

d. Hexane

Ans. a

28. Peziza shows which of the following fruiting bodies?

a. Cleistothecium

b. Apothecium

c. Perithecium

d. Hypothesium

Ans. b

29. Which of the following statements is/are correct?

a. Generation time is the time required by the cell to double

b. Generation time is not same for all microorganisms

c. Generation time is not same for a microorganism under all conditions

d. All the above

Ans. d

30. Rate of penetration of medium into a bacterial cell does not depend on:

a. Nutrient of the medium

b. Growth phase

c. Temperature

d. None

Ans. d

Food Microbiology MCQs With Answers pdf

31. Which of the following is NOT a platingg technique?

a. Spread plate technique

b. Tilt plate technique

c. Streak plate technique

d. Pour plate technique

Ans. b

32. Which of the following statements is/are NOT CORRECT?

a. The swab method is best suited for flexible, uneven, and heavily contaminated surfaces

b. Impingers are not suitable in air sampling because in this method specific quantity of air is difficult to be sampled

c. In case of ravimetric and volumetric samplin method, microbial concentrations can be reported as “per volume of diluent”

d. All of the above

Ans. b

33. Which of the following statements is/are correct?

a. Growth rate is recipprocal of generation time

b. Generation time of Bacillus subtilis is 8 min at 37 degree C in broth

c. Both a and b

d. Neither a nor b

Ans. a

34. Which of the following statements regarding log growth phase of bacterial growth curve is/are correct?

a. Cell division is at constant rate

b. Growth rate is maximum and constant

c. GGeneration time is shortest and constant

d. All of the above

Ans. d

35. Which of the following statements is/are not correct for the lag phase of the bacterial growth curve?

a. Gradual increase in cell number

b. This phase is used for fermentation

c. It is the phase of cell enlargement

d. All of the above

Ans. d

36. The difference between a chemostat and a turbidostat is/are:

a. The dilution rate in a turbidostart varies and in chemostat it is constant

b. Unlike chemostat, turbidostat doen not have any limiting nutrient

c. Turbidostat operates best at high dilution rates; the chemostat is most stable and effective at lower dilution rate

d. All ofthe above

Ans. d

Food Processing and Preservation MCQs

37. Turbidostat and chemostat are:

a. Continuous culture system

b. Instrument to enumerate the microbial cells

c. Type of sterilizer

d. Type of fermenter

Ans. a

38. The rate of nutrient exchange in a chemostat is expressed as:

a. Maintenance energy

b. Dilution rate

c. Flow rate of medium through the culture vessel

d. None of the above

Ans. b

39. A positive nitrate reduction test results in color:

a. Red

b. Blue

c. Green

d. Yellow

Ans. a

40. Which of the following is a rapid system for detecting the presence of foodborne pathoens?

a. PCR

b. Swab method

c. Streak technique

d. All of the above

Ans. a

41. The dye used in dye reduction test is/are:

a. Resazurin

b. Methylene blue

c. Both a and b

d. None

Ans. c

Multiple Choice Questions on Microorganisms

42. During the dye reduction test the resazurin is converted to:

a. Epinephrine

b. Resorufin

c. Restacline

d. None

Ans. b

43. During the dye reduction test using reazurin the color change taking place is:

a. Blue to green

b. Green to blue

c. Pink to blue

d. Blue to pink

Ans. d

44. Which of the following is NOT a method for quantifying the microbial population?

a. Gravimetric method

b. Total Plate Count (TPC) method

c. Standard plate counts (SPC) method

d. Most probable numbers (MPN) method

Ans. a

45. Which of the following is an example of protozoa?

a. Amoeba

b. Aspergillus

c. HIV

d. Hydra

Ans. a

46. Which of the following stains can be used to differentiate between dead and living cells?

a. Acridine orange

b. Methylene blue

c. Resazurin

d. All of the above

Ans. a

47. Acridine orange gives …………. color to the dead cells:

a. Orange

b. Blue

c. Green

d. Pink

Ans. c

48. DEFT is based on:

a. Conductance

b. Direct microbial count using microscope

c. Turbidit

d. Cellular activity

Ans. b

49. During measurement of the microbial load by ATP method, the oxidation of which compound is taken into consideration?

a. ATP

b. Luciferin

c. Acridine

d. Chitin

Ans. b

50. Cyanobacteria are also called:

a. Blue Green algae

b. Red Brown algae

c. Black & White algae

d. Green yellow algae

Ans. a

51. Prominent difference between prokaryotic and eukaryotic cells is the:

a. Larger size of prokaryotes

b. Lack of pigments in eukaryotes

c. Presence of a nucleus in eukaryotes

d. Presence of a cell wall in prokaryotes

Ans. c

52. The following part was absent in Leeuwenhoek’s microscope:

a. Focusing screw

b. Lens

c. Specimen holder

d. Condenser

Ans. d

53. The scientist who first disapproved the theory of spontaneous generation was:

a. Joseph Lister

b. Robert Koch

c. Francesco Redi

d. Louis Pasteur

Ans. c

54. The most responsible early microbiologist for developing the sterile laboratory technique was:

a. Louis Pasteur

b. Carl Von Line

c. Robert Koch

d. John Tyndall

Ans. c

55. The correct order of the taxonomic categories, going from most specific to most general is:

a. Kingdom, phylum, class, order, family, genus, species

b. Division, domain, kingdom, class, family, genus, species

c. Species, genus, family, order, class, phylum, kingdom

d. Species, family, class, order, phylum, kingdom

Ans. c

56. The term culture refers to the growth of microorganism in:

a. Rapid, an incubator

b. Macroscopic, media

c. Microscopic, the body

d. Artificial, colonies

Ans. b

57. A mixed culture is:

a. The same as a contained culture

b. One that has been adequately stirred

c. One that contains two or more known species

d. A pond sample containing algae and protozoa

Ans. c

58. Agar is superior to gelatin as a solidifying agent because agar:

a. Does not melt at room temperature

b. Solidifies at 75 degree C

c. Is not usually decomposed by microorganism

d. Both a and c

Ans. d

59. A subculture is a:

a. Colony growing beneath the media surface

b. Culture made from a contaminant

c. Culture made in an embryo

d. Culture made from an isolated colony

Ans. d

Food Microbiology Exam

60. The specimen for an electron microscope is always:

a. Stained with dyes

b. Sliced into thin sections

c. Killed

d. Viewed directly

Ans. c

61. Which of the following polymers is/are present in bacterial cell wall?

a. Techoic acids

b. Polysaccharide

c. Polypeptide

d. All of the above

Ans. d

62. Motility is best seen with a:

a. Hanging drop preparation

b. Negative stain

c. Streak plate

d. Flagellar

Ans. a

63. Bacteria tend to stain more readily with cationic dyes because:

a. Contain large amounts of alkaline substances

b. Contain large amounts of acidic substances

c. Are neutral

d. Have thick cell wall

Ans. b

64. The major locomotor structure in bacteria are:

a. Flagggella

b. Pili

c. Fimbriae

d. Cilia

Ans. a

65. Pili are tubular shafts in bacteria that serve as a means of:

a. Gram-positive, genetic exchange

b. Gram-positive, attachment

c. Gram-negative, genetic exchange

d. Gram-negative, protection

Ans. c

Food Preservation MCQs

66. A bacteria having flagella on both the sides are called as:

a. Monotrichus

b. Amphitrichus

c. Lophotrichus

d. Peritrichus

Ans. b

67. In general, fungi derive nutrients through:

a. Photosynthesis

b. Engulfing bacteria

c. Digesting organic substrates

d. Parasitism

Ans. c

General Microbiology Multiple Choice Questions pdf

68. A conidium is a/an spore, and a zygospore is a/an:

a. Sexual, asexual

b. Free, endo

c. Ascomycete, basidiomycete

d. Asexual, sexual

Ans. d

69. A virus is a tiny infectious:

a. Cell

b. Livin thing

c. Particle

d. Nucleic acid

Ans. c

70. Viruses are known to infect:

a. Plant

b. Bacteria

c. Animals

d. All organism

Ans. d

71. The general steps in a viral multiplication cycle are:

a. Adsorption, penetration, replication, maturation and release

b. Endocytosis, uncoating, replication, assembly, budding

c. Adsorption, uncoating, duplication, assembly and lysis

d. Endocytosis, penetration, replication, maturation and exocytosis

Ans. a

72. Enveloped viruses carry surface receptors called:

a. Buds

b. Spikes

c. Fibers

d. Sheaths

Ans. b

73. An obligate halophile requires high:

a. pH

b. Temperature

c. Salt

d. Pressure

Ans. c

74. Chemoautotrophs can survive on alone:

a. Minerals

b. CO2

c. Minerals and CO2

d. Methane

Ans. c

75. Psychrophies would be expected to grow:

a. In hot springs

b. On the human body

c. At refrigeration temperatures

d. At low pH

Ans. c

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