Which one of the following is not a nitrogen-fixing organism?

1.  Anabaena 2.  Nostoc
3.  Azotobacter 4.  Pseudomonas

Subtopic:  Microbes as Biofertilizer |
 88%
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Match each item in Column I [Diazotroph] with the feature in Column II and select the correct answer from the codes given below:

 

Column I

 

Column II

A.

Cyanobacteria

a.

Actinorhizal symbiont

B.

Frankia

b.

Do not form nodules

C.

Rhizobium

c.

Free-living nitrogen fixer

D.

Azotobacter

d.

Legume symbiont

Codes

A B C D
1. a b c d
2. b a c d
3. a b d c
4. b a d c
Subtopic:  Microbes as Biofertilizer |
 58%
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Identify the correct statements:
Statement I: Rhizobium forms symbiotic associations and forms nodules on the roots of non-leguminous plants.
Statement II: Azotobacter and Azospirillum can fix atmospheric nitrogen only as symbionts.
Statement III: Anabaena, Nostoc and Oscillatoria are autotrophic microbes capable of fixing atmospheric nitrogen.
1. Only Statement I and Statement II.
2. Only Statement III.
3. Only Statement I.
4. Statement I, Statement II and Statement III.
Subtopic:  Microbes as Biofertilizer |
 78%
From NCERT
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