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Nitrogen Fixation MCQs | Nitrogen Fixation Multiple Choice Questions and Answers

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Questions
1 Which of the following N2 fixer is involved in symbiotic association with legumes forming root nodules?
A Azotobacter
B Rhodospirillum
C Clostridium
D Rhizobium

Answer: Rhizobium
2 Splitting of dinitrogen molecule into free nitrogen atom in biological N2 fixation is carried out by
A Hydrogenase
B Dinitrogenase
C Nitrate Reductase
D Nitrogenase

Answer: Nitrogenase
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3 Industrial fixation is accomplished by
A Haber process
B Helmonts process
C Friedel- Crafts reaction
D None of these

Answer: Haber process
4 Leghaemoglobin creates
A Suitable environment for nodule formation
B Required oxygen concentration for optimum activity of nitrogenase
C Aerobic condition for optimum activity of nitrogenase
D Anaerobic condition for optimum activity of nitrogenase

Answer: Anaerobic condition for optimum activity of nitrogenase
5 The reaction of glutamate and NH4+ to yield glutamine is catalyzed by
A Glutamine synthase
B Glutamate synthase
C Adenylyltransferase
D Uridylyltransferase

Answer: Glutamine synthase
6 Which of the following catalyzes reactions that incorporate nitrogen derived from glutamine?
A Glutamine amidotransferase
B Glutamine synthase
C Glutamate synthase
D Adenylyltransferase

Answer: Glutamine amidotransferase
7 Formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds is called as
A Nitrogen assimilation
B Nitrogen fixation
C Nitrification
D Denitrification

Answer: Nitrogen assimilation
8 Ammonia or ammonium is oxidized to nitrite followed by the oxidation of nitrite to nitrate is called as
A Nitrogen fixation
B Nitrification
C Denitrification
D Nitrogen assimilation

Answer: Nitrification
9 Nitrate is reduced and ultimately produces N2 through a series of intermediate gaseous nitrogen oxide products is called as
A Nitrogen fixation
B Nitrification
C Nitrogen assimilation
D Denitrification

Answer: Denitrification
10 The conversion of nitrogen to ammonia or nitrogenous compounds is called as
A Nitrogen fixation
B Nitrogen assimilation
C Denitrification
D Nitrification

Answer: Nitrogen fixation
11 Plants cannot absorb molecular N2 in the atmosphere because
A N2 has triple bonds making it highly stable
B N2 has double bonds making it highly stable
C Abundance in the atmosphere inhibits absorption
D None of these

Answer: N2 has triple bonds making it highly stable
12 Anabaena, a N2 fixer is present in the root pockets of
A Marselia
B Salvinia
C Pistia
D Azolla

Answer: Azolla
13 The conversion of amino acids to ammonium by soil decomposers is called
A Ammonification
B Mineralization
C Deamination
D Both A And B

Answer: Both A And B
14 To fix one molecule of nitrogen
A 6 ATP molecules are required
B 12 ATP molecules are required
C 20 ATP molecules are required
D 16ATP molecules are required

Answer: 16ATP molecules are required
15 Conversion of NO2- to NO3- is carried out by
A Nitrosomonas
B Nitrososcoccus
C Nitrobacter
D Clostridium

Answer: Nitrobacter
16 Uridylylation and deuridylylation of PII are brought about by a single enzyme
A Adenylyltransferase
B Glutamate synthase
C Dinitrogenase
D Uridylyltransferase

Answer: Uridylyltransferase
17 An intermediate of the citric acid cycle that undergoes reductive amination with glutamine as nitrogen donor is
A α-ketoglutarate
B Glutamine
C NADPH
D All of above

Answer: α-ketoglutarate
18 Conversion of nitrogen to ammonia or nitrogenous compounds is termed as
A Nitrification
B Denitrification
C Nitrogen fixation
D All of these

Answer: Nitrogen fixation
19 Plants absorbs N2 in the form of
A Nitrites (NO2-)
B Nitrates (NO3-)
C Ammonium (NH4+)
D All Of The Above

Answer: All Of The Above
20 Symbiotic N2 fixing cyanobacteria are present in all except
A Gnetum
B Anthoceros
C Azolla
D None of these

Answer: Gnetum