Explore topic-wise MCQs in Microbiology.

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.

101.

Medium acid foods with a pH between 5.3 and 4.5 are likely to undergo

A. flat sour spoilage
B. putrefaction
C. both (a) and (b)
D. TA spoilage
Answer» E.
102.

Floaters or bloaters may result from

A. hollow cucumbers
B. gas being formed by yeasts
C. hetero fermentative lactic acid bacteria
D. all of these
Answer» E.
103.

Most spoilage bacteria grow at

A. acidic pH
B. alkaline pH
C. neutral pH
D. any of the pH
Answer» D. any of the pH
104.

Bacterial cell grown on hydrocarbon wastes from the petroleum industry are a source of _____________

A. carbohydrates
B. proteins
C. vitamins
D. fats
Answer» C. vitamins
105.

How many tons of protein can be produced by algae grown in pond in a year?

A. 1000
B. 1
C. 50
D. 20
Answer» E.
106.

Yeast-cell crops harvested from the vats is used to produce which of the following compounds?

A. alcoholic beverages
B. enzymes
C. antibiotics
D. organic acids
Answer» B. enzymes
107.

Which of the following microorganism have a high vitamin content?

A. bacteria
B. yeast
C. algae
D. protozoa
Answer» C. algae
108.

What is the range of protein content in yeast cells?

A. 69%
B. 12-15%
C. 20-40%
D. 40-50%
Answer» E.
109.

Which of the following method is used for treatment of water used for the depuration of shellfish?

A. Chemicals
B. Radiation
C. Low temperature
D. Osmotic pressure
Answer» C. Low temperature
110.

Acetic acid and lactic acid are used for __________________

A. curing meats
B. preservation of color
C. preservation of pickles
D. inhibiting mold growth
Answer» D. inhibiting mold growth
111.

Which of the following microbe is used in the production of blue cheese?

A. Streptococcus thermophilus
B. Lactobacillus bulgaricus
C. Penicillium roqueforti
D. Rhizopus stolonifer
Answer» D. Rhizopus stolonifer
112.

Sterilization occurs at high temperatures for long periods of time.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
113.

Which of the following type of spoilage occurs in fresh meat?

A. Souring
B. Greening
C. Putrefaction
D. Moldy
Answer» D. Moldy
114.

Which of the following microorganism is eliminated in canned foods?

A. Mycobacterium tuberculosis
B. Coxiella burnetii
C. Clostridium botulinum
D. Lactobacillus
Answer» D. Lactobacillus
115.

The temperatures used for canning foods ranges from ____________________

A. 0-20 degree C
B. 20-60 degree C
C. 60-100 degree C
D. 100-121 degree C
Answer» E.
116.

The thermophilic anaerobe spoilage of low and medium acid canned products are caused by _____________

A. Bacilllus stearothemophilus
B. Clostridium thermosaccharolyticum
C. Bacillus thermoacidurans
D. Clostridium sporogenes
Answer» C. Bacillus thermoacidurans
117.

In the high-temperature short-time (HTST) method of pasteurization, milk is exposed to a temperature of _________

A. 132 degree F
B. 145 degree F
C. 161 degree F
D. 120 degree F
Answer» D. 120 degree F
118.

Tuberculosis brucellosis is caused by the pathogen from an infected cow.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
119.

In which of the following biochemical types of microorganisms a slime layer or capsule is formed on the cells?

A. Acid producers
B. Gas producers
C. Ropy or stringy fermentation
D. Proteolytic
Answer» D. Proteolytic
120.

The coloration of the milk is caused by which of the following organism?

A. Pseudomonas sp.
B. Bacillus sp.
C. Penicillium sp.
D. Streptococcus sp.
Answer» B. Bacillus sp.
121.

Which among the following group of microorganisms are found in the ducts of cow’s mammary glands?

A. Coliforms
B. Lactobacilli
C. Micrococci
D. Microbacteria
Answer» D. Microbacteria
122.

What is the pH of bananas?

A. 2.3
B. 5.0
C. 7.0
D. 12.0
Answer» C. 7.0
123.

Which of the following organism occurs on the skin of fresh poultry?

A. pseudomonads
B. staphylococci
C. micrococci
D. enterococci
Answer» B. staphylococci
124.

Raw milk of good sanitary quality will develop sweet flavour.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
125.

Belt filter presses are used in which of the following process?

A. Thickening
B. Stabilization
C. Dewatering
D. Disposal
Answer» D. Disposal
126.

The upper region of the trickling filter is favorable for the growth of _____________

A. fungi
B. protozoa
C. algae
D. bacteria
Answer» D. bacteria
127.

Among the following which microorganism acts as a representative of fecal streptococci group?

A. Streptococcus faecalis
B. Streptococcus bovis
C. Streptococcus equinus
D. Streptococcus faecium
Answer» B. Streptococcus bovis
128.

Coliforms are natural inhabitants of the large intestine of human and animals.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
129.

Which of the following sewerage systems carry domestic and industrial waste water?

A. sanitary sewers
B. storm sewers
C. combined sewers
D. storm and combined sewers
Answer» B. storm sewers
130.

Which of the following is a strict anaerobe?

A. Enterobacter
B. Alcaligenes
C. Pseudomonas
D. Methanosarcina
Answer» E.
131.

In which of the following treatment involve oxidation of organic constituents of the wastewater?

A. Primary treatment
B. Secondary treatment
C. Advanced treatment
D. Final treatment
Answer» C. Advanced treatment
132.

S. patorianns can cause

A. cloudiness in beer
B. ester like taste in beer
C. stringent taste in beer
D. bitter taste
Answer» B. ester like taste in beer
133.

Hollow pickles are obtained as a result of

A. loose packing in the vat
B. too strong or too weak brine
C. both (a) and (b)
D. none of these
Answer» D. none of these
134.

The most commonly used medium for the build up of cultures and the production of baker's yeast consist of

A. molasses and minerals
B. molasses, minerals and salts
C. molasses
D. molasses, lactose
Answer» C. molasses
135.

What will be the plate count of good quality water?

A. 10 per ml
B. 50 per ml
C. 100 per ml
D. 1000 per ml
Answer» D. 1000 per ml
136.

Too long a fermentation of sauerkraut may favour the growth of

A. Lactobacillus lactis
B. Lactobacillus brevis
C. Bacillus subtilis
D. none of these
Answer» C. Bacillus subtilis
137.

The spoilage most commonly occurring in wine is tourne which refers to

A. acid formation from aldehyde and ketones
B. acid formation from sugars, glucose and fructose
C. both (a) and (b)
D. none of the above
Answer» C. both (a) and (b)
138.

The principal microorganism for yogurt is ______________________

A. Streptococcus thermophilus
B. Leuconostoc citrovorum
C. Lactobacillus acidophilus
D. Streptococcus lactis
Answer» B. Leuconostoc citrovorum
139.

Canned sweetened condensed milk may become thickened by

A. Bacillus species
B. Clostridium species
C. Micrococcus species
D. Saccharomyces species
Answer» D. Saccharomyces species
140.

Treatment of municipal water supplies is based upon

A. coagulation, filtration, chlorination
B. chlorination, filtration, coagulation
C. filtration, coagulation, chlorination
D. coagulation, chlorination, filtration
Answer» B. chlorination, filtration, coagulation
141.

Which of the following gases are produced in large amounts during sludge digestion?

A. methane
B. carbon-dioxide
C. hydrogen
D. nitrogen
Answer» B. carbon-dioxide
142.

The method of successful treatment of botulism prior to appearance of botulism symptoms involve administration of

A. antibiotic
B. analgesic
C. antitoxin
D. antipyretic
Answer» D. antipyretic
143.

At what temperature pasteurization of milk takes place?

A. 65° C
B. 37° C
C. 62.8° C
D. 45° C
Answer» D. 45° C
144.

Examination of the presence / absence of organisms refers to

A. incubation of a food suspension in an enrichment medium followed by inoculation on to a suitable selective medium.
B. incubation of a food suspension in an enrichment medium followed by inoculation on to a non-selective medium.
C. incubation of a food suspension in an enrichment medium
D. none of the above
Answer» B. incubation of a food suspension in an enrichment medium followed by inoculation on to a non-selective medium.
145.

Biomass

A. provides the U.S. with about 50% of its energy
B. consists largely of wood, animal, and human waste
C. is unlikely to be a major source of energy globally
D. offers the consumer high quality energy with low environmental impact
Answer» C. is unlikely to be a major source of energy globally
146.

The putrifactive anaerobes grow best in the

A. low acid canned foods
B. medium acid canned foods
C. high acid canned foods
D. any of these
Answer» B. medium acid canned foods
147.

Sarcina sickness of beer is caused by

A. Saccharomyces cerevisiae
B. Pedicoccus cerevisiae
C. S. carlsbergensis
D. Zygomonas anaeroium
Answer» C. S. carlsbergensis
148.

The milk streptococci produce acetoin that gets spontaneously oxidized yielding a flavorings agent (responsible for aroma of butter) that is

A. acetone
B. acetyl coA
C. butyric acid
D. diacetyl
Answer» E.
149.

The botulism intoxication occurs due to

A. an enterotoxin
B. neurotoxin
C. mycotoxin
D. all of these
Answer» C. mycotoxin
150.

Which of the following beer is of Japanese origin with an alcohol content of 14 to 17%?

A. Sake
B. Pulpue
C. Sonti
D. Lager
Answer» B. Pulpue