Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere?
 
1. Aerobic nitrate oxidation, and nitrite reduction
2. Decomposition of organic nitrogen, and conversion of dinitrogen to ammonium compounds
3. Enteric fermentation in cattle, and nitrogen fixation by Rhizobium in root nodules of legumes
4. Anaerobic ammonium oxidation, and denitrification

 
Subtopic:  Nitrogen Fixation | Nitrogen Metabolism |
 56%
From NCERT
NEET - 2013
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Please attempt this question first.

Read the following four statements (I-IV):

I. Both, photophosphorylation and oxidative phosphorylation involve uphill transport of protons across the
membrane
II. In dicot stems, a new cambium originates from cells of pericycle at the time of secondary growth
III. Stamens in flowers of Gloriosa and Petunia are polyandrous
IV. Symbiotic nitrogen-fixers occur in a free-living state and also in soil


How many of the above statements are right?

1.  Three 

2. Four 

3. One 

4. Two 

Subtopic:  Nitrogen Fixation | Nodule formation |
AIPMT - 2012
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NEET 2023 - Target Batch - Aryan Raj Singh
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Nitrifying bacteria:

1.  convert free nitrogen to nitrogen compounds
2.  convert proteins into ammonia
3.  reduce nitrates to free nitrogen
4.  oxidize ammonia to nitrates

Subtopic:  Nitrogen Fixation |
 58%
From NCERT
AIPMT - 2011
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NEET 2023 - Target Batch - Aryan Raj Singh
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NEET 2023 - Target Batch - Aryan Raj Singh

The free-living, anaerobic nitrogen-fixer is:

1. Beijerinckia

2. Rhodospirillum

3. Rhizobium

4. Azotobacter

Subtopic:  Nitrogen Fixation |
 73%
From NCERT
AIPMT - 2010
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NEET 2023 - Target Batch - Aryan Raj Singh
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NEET 2023 - Target Batch - Aryan Raj Singh

Study the cycle shown below and select the option which gives the correct words for all four blanks A, B, C, and D:

   

 Options:

A B C D
1. Denitrification Ammonification Plants Animals
2. Nitrification Denitrification Animals Plants
3. Denitrification Nitrification Plants Animals
4. Nitrification Ammonification Animals Plants
Subtopic:  Nitrogen Fixation |
 81%
From NCERT
AIPMT - 2010
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NEET 2023 - Target Batch - Aryan Raj Singh
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NEET 2023 - Target Batch - Aryan Raj Singh

Which of the following is a symbiotic nitrogen fixer?
1. Glomus
2. Azotobacter
3. Frankia
4. Azolla

Subtopic:  Nitrogen Fixation | Genetics & Biochemistry of Nitrogen Fixation |
 71%
From NCERT
AIPMT - 2009
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NEET 2023 - Target Batch - Aryan Raj Singh
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NEET 2023 - Target Batch - Aryan Raj Singh

Nitrogen-fixation in root nodules of Alnus is brought about by:
1. Bradyrhizobium 2. Clostridium
3. Frankia 4. Azorhizobium
Subtopic:  Nitrogen Fixation | Genetics & Biochemistry of Nitrogen Fixation |
 94%
From NCERT
AIPMT - 2008
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NEET 2023 - Target Batch - Aryan Raj Singh
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NEET 2023 - Target Batch - Aryan Raj Singh

Which of the following is a flowering plant with nodules containing filamentous nitrogen-fixing microorganism?

1. Casuarina equisetifolia

2. Crotolaria juncea

3. Cycas revoluta

4. Cicer arietinum

Subtopic:  Nitrogen Nutrition in Plants | Nitrogen Fixation |
AIPMT - 2007
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NEET 2023 - Target Batch - Aryan Raj Singh
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