Explore topic-wise MCQs in Microbiology.

This section includes 24 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

Certain strains of var. may produce

A. bitter flavor
B. acid flavor
C. burnt or caramel flavor
D. none of these
Answer» D. none of these
Discussion
2.

in butter which is blamed on is also called as

A. rabbito
B. putridity
C. both (a) and (b)
D. none of these
Answer» D. none of these
Discussion
3.

produces a

A. bluish gray to brownish color in milk in its pure form
B. brownish color to bluish gray in milk in its pure form
C. gray to brownish color in milk
D. yellow color in milk
Answer» B. brownish color to bluish gray in milk in its pure form
Discussion
4.

in mildly salted butter may cause

A. black smudge
B. greenish areas
C. pink color
D. none of these
Answer» B. greenish areas
Discussion
5.

Surface taint in butter which is blamed on Pseudomonas putrefaciens is also called as

A. rabbito
B. putridity
C. both (a) and (b)
D. none of these
Answer» D. none of these
Discussion
6.

Pseudomonas nigrifaciens in mildly salted butter may cause

A. black smudge
B. greenish areas
C. pink color
D. none of these
Answer» B. greenish areas
Discussion
7.

Esters like flavors in butter are resulted from the action of

A. <i>P. mephitica</i>
B. <i>Aeromonas hydrophila</i>
C. <i>P. fragi</i>
D. <i>Pseudomonas synxantha</i>
Answer» D. <i>Pseudomonas synxantha</i>
Discussion
8.

Ropiness caused by Enterobacter usually is

A. worse at the middle of the milk
B. worse at the bottom of the milk
C. worse near the top of the milk
D. all of these
Answer» D. all of these
Discussion
9.

A brown color in milk may result from

A. <i>Pseudomonas putrefaciens</i>
B. the enzymatic oxidation of tyrosine by
C. <i> P. fluorescens</i>
D. both (a) and (b)
E. <i>S. marcescens</i>
Answer» D. both (a) and (b)
Discussion
10.

Which of the following species of Clostridium is responsible for formation of dark green to black colours in cheese?

A. <i>Clostridium tyrobutyricum</i>
B. <i>Clostridium sporogenes</i>
C. <i>Clostridium herbarum</i>
D. None of these
Answer» D. None of these
Discussion
11.

Certain strains of Streptococcus lactis var. maltigenes may produce

A. bitter flavor
B. acid flavor
C. burnt or caramel flavor
D. none of these
Answer» D. none of these
Discussion
12.

Cheese with too low an acidity because of the addition of cream or the failure of the starter often is made gelatinous or slimy by

A. Pseudomonas
B. <i>P. fragi</i>
C. <i>Alcaligenes metalcaligenes</i>
D. all of these
Answer» E.
Discussion
13.

Pseudomonas syncyanea produces a

A. bluish gray to brownish color in milk in its pure form
B. brownish color to bluish gray in milk in its pure form
C. gray to brownish color in milk
D. yellow color in milk
Answer» B. brownish color to bluish gray in milk in its pure form
Discussion
14.

Acidophilus milk which is used for its therapeutic properties in intestinal disorders requires for its manufacture a pure culture of

A. <i>Lactobacillus bulgaricus</i>
B. <i>Streptococcus thermophilics</i>
C. <i>Lactobacillus acidophilus</i>
D. None of the above
Answer» D. None of the above
Discussion
15.

A yellow color in the creamy layer of milk may be caused by

A. <i>Pseudomonas synxantha</i>
B. <i>Pseudomonas syncyanea</i>
C. both (a) and (b)
D. <i>S. marcescens</i>
Answer» B. <i>Pseudomonas syncyanea</i>
Discussion
16.

An alkaline reaction in milk is caused by the alkali formers bacteria as

A. <i>Pseudomonas fluorescens</i>
B. <i>A. viscolactis</i>
C. both (a) and (b)
D. none of these
Answer» D. none of these
Discussion
17.

Bacterial ropiness in milk is caused by

A. slimy capsular material from the cells usually gums or mucins
B. slimy capsular material from the cells usually proteins
C. slimy capsular material from the cells usually lipids
D. all of the above
Answer» B. slimy capsular material from the cells usually proteins
Discussion
18.

Fishiness in butter is caused by

A. <i>Aeromonas hydrophila</i>
B. <i>Pseudomonas synxantha</i>
C. <i>Pseudomonas syncyanea</i>
D. none of these
Answer» B. <i>Pseudomonas synxantha</i>
Discussion
19.

The chief type of spoilage in sweetened condensed milk may be

A. gas formation by sucrose fermenting yeasts
B. thickening caused by micrococci
C. mold colonies growing on the surface
D. all of the above
Answer» E.
Discussion
20.

Non bacterial ropiness or sliminess in milk and milk products may be due to the

A. stringiness caused by mastitis and in particular by fibrin and leucocytes from the cow's blood.
B. sliminess resulting from the thickness of the cream
C. stringiness due to thin films of casein or lactalbumin during cooling
D. all of the above
Answer» E.
Discussion
21.

The yoghurt is made from

A. <i>Lactobacillus bulgaricus</i>
B. <i>Streptococcus thermophilus</i>
C. <i>S. cremoris</i>
D. mixed culture of (a) and (b)
Answer» E.
Discussion
22.

Cheese cancer of Swiss and similar cheese is caused by

A. <i>Oospora Crustacea</i>
B. <i>Oospora caseovorans</i>
C. <i>Oospora aurianticum</i>
D. none of these
Answer» C. <i>Oospora aurianticum</i>
Discussion
23.

Swelling of the can is caused primarily by

A. gas forming, anaerobic spore formers
B. gas forming, aerobic spore formers
C. both (a) and (b)
D. none of these
Answer» B. gas forming, aerobic spore formers
Discussion
24.

Bulgarian butter milk is made with the help of

A. <i>Lactobacillus bulgaricus</i>
B. <i>Streptococcus lactis</i>
C. <i>Streptococcus thermophilus</i>
D. <i>S. cremoris</i>
Answer» B. <i>Streptococcus lactis</i>
Discussion