37 + Mcqs in Microbiology of Soils Page 1 McqOptions

1.	Which of the following microorganism use HS as the electron donor to reduce carbon dioxide?
A.	Both (a) and (b)
Answer» D.

Discussion

2.	In the process of nitrogen fixation, which of the following microorganism is involved?
A.	Non symbiotic microorganisms only
B.	Symbiotic microorganisms only
C.	Non symbiotic and symbiotic microorganisms only
D.	None of the above
Answer» D. None of the above

Discussion

3.	An example of a symbiotic nitrogen fixer is
A.	<i>Azotobacter</i>
B.	<i>Beijerinckia</i>
C.	<i>Clostridium</i>
D.	<i>Rhizobium </i>
Answer» E.

Discussion

4.	The transformation of nitrates to gaseous nitrogen is accomplished by microorganisms in a series of biochemical reactions. The process is known as
A.	nitrification
B.	denitrification
C.	nitrogen fixation
D.	ammonification
Answer» C. nitrogen fixation

Discussion

5.	The groups of symbiotic bacteria, which have the ability to fix nitrogen
A.	derive their food and minerals from the legume, and in turn they supply the legume with some or all of its nitrogen
B.	grow together for a mutual benefit is called symbiosis and so these bacteria are called symbiotic nitrogen-fixing bacteria
C.	these bacteria are from the genus, Rhizobium
D.	all of the above
Answer» E.

Discussion

6.	Nitrifying bacteria can not be isolated directly by the usual techniques employed to isolate hetrotrophic bacteria. The reasons may be due to
A.	slow growth
B.	medium growth
C.	fast growth
D.	none of these
Answer» B. medium growth

Discussion

7.	The phenomenon of commensalism refers to a relationship between organisms in which
A.	one species of a pair benefits
B.	both the species of a pair benefit
C.	one species of a pair is more benefited
D.	none of the above
Answer» B. both the species of a pair benefit

Discussion

8.	The diagnostic enzyme for denitrification is
A.	nitrate reductase
B.	nitrate oxidase
C.	nitro oxidoreductase
D.	none of these
Answer» B. nitrate oxidase

Discussion

9.	Which of the following microorganism use H2S as the electron donor to reduce carbon dioxide?
A.	<i>Chromaticum</i>
B.	<i>Chlorobium</i>
C.	Both (a) and (b)
D.	<i>Rhodomicrobium</i>
Answer» D. <i>Rhodomicrobium</i>

Discussion

10.	The population of algae in soil is __________ that of either bacteria or fungi.
A.	generally smaller than
B.	generally greater than
C.	equal to
D.	none of these
Answer» B. generally greater than

Discussion

11.	A heterocyst is
A.	a type of spore
B.	a terminally differentiated cell that fixes nitrogen
C.	the progenitor of cyanobacterial vegetative cells
D.	a cell that carries out oxygenic photosynthesis
Answer» C. the progenitor of cyanobacterial vegetative cells

Discussion

12.	Nitrogen fixation refers to the direct conversion of atmospheric nitrogen gas into
A.	ammonia
B.	glucose
C.	ATP
D.	nitrate
Answer» B. glucose

Discussion

13.	The nonsymbiotic bacteria which fix nitrogen live in the soil independently are
A.	<i>Azotobacter </i>
B.	<i>Clostridium </i>
C.	considerably less important in comparison to the symbiotic bacteria
D.	all of the above
Answer» E.

Discussion

14.	Which of the following is not the biofertilisers producing bacteria?
A.	Nostoc
B.	Anabaena
C.	Both (a) and (b)
D.	Clostridium
Answer» E.

Discussion

15.	Most soil protozoa are flagellates or amoebas, having their dominant mode of nitrogen as
A.	ingestion of bacteria
B.	ingestion of mold
C.	ingestion of fungi
D.	all of these
Answer» B. ingestion of mold

Discussion

16.	Which of the following is capable of oxidizing sulfur to sulfates?
A.	<i>Thiobacillus thiooxidans</i>
B.	<i>Desulfotomaculum</i>
C.	<i>Rhodospirillum</i>
D.	<i>Rhodomicrobium</i>
Answer» B. <i>Desulfotomaculum</i>

Discussion

17.	Denitrification may be distinguished as
A.	dissimilative
B.	assimilative
C.	both (a) and (b)
D.	blue baby syndrome
Answer» D. blue baby syndrome

Discussion

18.	The conversion of molecular nitrogen into ammonia is known as
A.	nitrification
B.	denitrification
C.	nitrogen fixation
D.	ammonification
Answer» D. ammonification

Discussion

19.	Which of the following species of different genera of bacteria are not capable of transforming nitrate to nitrogen?
A.	<i>Achromobacter</i>
B.	<i>Agrobacterium</i>
C.	<i>Alcaligenes </i>
D.	None of these
Answer» E.

Discussion

20.	Some microorganisms have the ability to increase the nitrogen content of soils, are called as
A.	nitrogen fixation
B.	denitrification
C.	nitrification
D.	all of these
Answer» B. denitrification

Discussion

21.	__________ play a key role in the transformation of rock to soil.
A.	Cyanobacteia
B.	Pectin decomposing bacteria
C.	Nitrifying bacteria
D.	De-nitrifying bacteria
Answer» B. Pectin decomposing bacteria

Discussion

22.	The groups of bacteria which have the ability to fix nitrogen from air to soil are
A.	symbiotic
B.	nonsymbiotic
C.	both (a) and (b)
D.	none of these
Answer» D. none of these

Discussion

23.	The nitrogenase consists of
A.	dinitrogenase
B.	dinitrogenase reductase
C.	both (a) and (b)
D.	none of these
Answer» D. none of these

Discussion

24.	For rapid decomposition by microbes, the substrate should have a C/N ratio of
A.	10-20
B.	20-30
C.	30-40
D.	60-80
Answer» D. 60-80

Discussion

25.	Which are the main source of biofertilisers?
A.	Cyanobacteria
B.	Bacillus
C.	Streptococcus
D.	None of these
Answer» B. Bacillus

Discussion

26.	The diagnostic enzyme for nitrogen-fixing organisms is
A.	nitrogenase
B.	nitrate reductase
C.	nitrate oxidase
D.	none of these
Answer» B. nitrate reductase

Discussion

27.	Which of the following fungi on infecting crop roots can improve their uptake of phosphorus and other nutrients?
A.	<i>Saccharomyces cerevisiae</i>
B.	VA Mycorrhiza
C.	<i>Candida torulopsis</i>
D.	<i>Aspergillus niger</i>
Answer» C. <i>Candida torulopsis</i>

Discussion

28.	Which of the following soil microorganism is involved in the reduction of sulfates to H2S?
A.	<i>Thiobacillus thiooxidans</i>
B.	<i>Desulfotomaculum</i>
C.	<i>Rhodospirillum</i>
D.	<i>Rhodomicrobium</i>
Answer» C. <i>Rhodospirillum</i>

Discussion

29.	Assimilative denitrification is done by
A.	plants
B.	fungi
C.	prokaryotes
D.	all of these
Answer» E.

Discussion

30.	Degree of compost maturity can be assesed by
A.	infrared technique
B.	germination test
C.	both (a) and (b)
D.	none of the above
Answer» D. none of the above

Discussion

31.	The physical structure of soil is improved by the accumulation of
A.	mold mycelium
B.	minerals
C.	water
D.	all of these
Answer» B. minerals

Discussion

32.	The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?
A.	Hydrolytic
B.	Transitional
C.	methanogenic
D.	All of these
Answer» E.

Discussion

33.	The microbial ecosystem of soil includes
A.	biotic components of soil
B.	abiotic components of soil
C.	biotic and abiotic components of soil
D.	none of the above
Answer» D. none of the above

Discussion

34.	Syntrophism involves
A.	exchange of nutrients between two species
B.	exchange of nutrients among species
C.	no exchange of nutrients between two species
D.	no exchange of nutrients among species
Answer» B. exchange of nutrients among species

Discussion

35.	The crops which are involved in nitrogen fixation are
A.	alfalfa and clover
B.	soybean
C.	bean and lupine
D.	all of these
Answer» E.

Discussion

36.	Bacteria, as a group, are responsible for
A.	nitrogen oxidation
B.	sulfur oxidation
C.	nitrogen fixation
D.	all of these
Answer» E.

Discussion

37.	The organisms responsible for the characteristic musty or earth odor of a freshly plowed field is/are
A.	Nocardia
B.	Streptomyces
C.	Micromonospora
D.	all of these
Answer» E.

Discussion

Explore topic-wise MCQs in Microbiology.

Which of the following microorganism use HS as the electron donor to reduce carbon dioxide?

In the process of nitrogen fixation, which of the following microorganism is involved?

An example of a symbiotic nitrogen fixer is

The transformation of nitrates to gaseous nitrogen is accomplished by microorganisms in a series of biochemical reactions. The process is known as

The groups of symbiotic bacteria, which have the ability to fix nitrogen

Nitrifying bacteria can not be isolated directly by the usual techniques employed to isolate hetrotrophic bacteria. The reasons may be due to

The phenomenon of commensalism refers to a relationship between organisms in which

The diagnostic enzyme for denitrification is

Which of the following microorganism use H2S as the electron donor to reduce carbon dioxide?

The population of algae in soil is __________ that of either bacteria or fungi.

A heterocyst is

Nitrogen fixation refers to the direct conversion of atmospheric nitrogen gas into

The nonsymbiotic bacteria which fix nitrogen live in the soil independently are

Which of the following is not the biofertilisers producing bacteria?

Most soil protozoa are flagellates or amoebas, having their dominant mode of nitrogen as

Which of the following is capable of oxidizing sulfur to sulfates?

Denitrification may be distinguished as

The conversion of molecular nitrogen into ammonia is known as

Which of the following species of different genera of bacteria are not capable of transforming nitrate to nitrogen?

Some microorganisms have the ability to increase the nitrogen content of soils, are called as

__________ play a key role in the transformation of rock to soil.

The groups of bacteria which have the ability to fix nitrogen from air to soil are

The nitrogenase consists of

For rapid decomposition by microbes, the substrate should have a C/N ratio of

Which are the main source of biofertilisers?

The diagnostic enzyme for nitrogen-fixing organisms is

Which of the following fungi on infecting crop roots can improve their uptake of phosphorus and other nutrients?

Which of the following soil microorganism is involved in the reduction of sulfates to H2S?

Assimilative denitrification is done by

Degree of compost maturity can be assesed by

The physical structure of soil is improved by the accumulation of

The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?

The microbial ecosystem of soil includes

Syntrophism involves

The crops which are involved in nitrogen fixation are

Bacteria, as a group, are responsible for

The organisms responsible for the characteristic musty or earth odor of a freshly plowed field is/are