Explore topic-wise MCQs in Microbiology.

This section includes 20 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

Which among the following develop in the upper portion of the Winogradsky column?

A. Sulfate-reducing bacteria
B. Green-sulfur bacteria
C. Purple-sulfur bacteria
D. Thiobacilli
Answer» E.
2.

The reduction of sulphates and sulphites to hydrogen sulphide is done by which group of bacteria?

A. aerobic sulfate-reducing bacteria
B. photosynthetic sulphur bacteria
C. anaerobic sulphate-reducing bacteria
D. heterotrophic bacteria
Answer» D. heterotrophic bacteria
3.

The Winogradsky column experiment is done in the dark.

A. True
B. False
Answer» C.
4.

Sulphates are reduced to hydrogen sulphide by _____________________

A. Desulfotomaculum sp.
B. Thiobacillus thiooxidans
C. Photosynthetic sulfur bacteria
D. Rhodospirillum
Answer» B. Thiobacillus thiooxidans
5.

Cysteine breaks down in presence of cysteine desulfurase to give _________________

A. oxaloacetic acid
B. sulphuric acid
C. pyruvic acid
D. glyoxalate
Answer» D. glyoxalate
6.

Which among the following are the most important agents for carbon dioxide fixation?

A. bacteria
B. fungi
C. algae
D. protozoa
Answer» D. protozoa
7.

SULPHATES_ARE_REDUCED_TO_HYDROGEN_SULPHIDE_BY______________________?$

A. Desulfotomaculum sp.
B. Thiobacillus thiooxidans
C. Photosynthetic sulfur bacteria
D. Rhodospirillum
Answer» B. Thiobacillus thiooxidans
8.

The reduction of sulphates and sulphites to hydrogen sulphide is done by which group of bacteria?$

A. aerobic sulfate-reducing bacteria
B. photosynthetic sulphur bacteria
C. anaerobic sulphate-reducing bacteria
D. heterotrophic bacteria
Answer» D. heterotrophic bacteria
9.

The_Winogradsky_column_experiment_is_done_in_the_dark.$

A. True
B. False
Answer» C.
10.

Which among the following is a non-sulfur purple bacteria?

A. Rhodomicrobium
B. Thiobacillus
C. Chromatium
D. Chlorobium
Answer» B. Thiobacillus
11.

Purple and green sulfur bacteria use ___________________ as the electron donor to reduce carbon dioxide.

A. S<sup>2-</sup>
B. SO4<sup>2-</sup>
C. H<sup>2</sup>S
D. Organic acids
Answer» D. Organic acids
12.

Which among the following develop in the upper portion of the Winogradsky column?

A. Sulfate-reducing bacteria
B. Green-sulfur bacteria
C. Purple-sulfur bacteria
D. Thiobacilli
Answer» E.
13.

Which of the following processes is performed by Thiobacillus thiooxidans?

A. converting sulphur to sulphates
B. converting sulphur to sulphides
C. converting sulphur to sulphites
D. converting organic sulphur to inorganic sulphur
Answer» B. converting sulphur to sulphides
14.

Cysteine breaks down in presence of cysteine desulfurase to give _________________

A. oxaloacetic acid
B. sulphuric acid
C. pyruvic acid
D. glyoxalate
Answer» D. glyoxalate
15.

Cellobiose is metabolized directly by many microorganisms.

A. True
B. False
Answer» C.
16.

In carbon cycle flow of energy is _________________

A. bidirectional
B. linear
C. cyclic
D. irreversible
Answer» C. cyclic
17.

The amount of organic material in the forest soil remains approximately the same from year to year.

A. True
B. False
Answer» B. False
18.

Cellulose is degraded to cellobiose by the enzyme __________________

A. cellulase
B. beta-glucosidase
C. hexokinase
D. cellulose dehydrogenase
Answer» B. beta-glucosidase
19.

Fresh air contains approximately ______ percent carbon dioxide by volume.

A. 0.01
B. 2
C. 5
D. 0.03
Answer» E.
20.

Which among the following are the most important agents for carbon dioxide fixation?

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