Which of the following is a non–symbiotic nitrogen fixing bacteria?
1. Rhizobium
2. Mycorrhiza
3. Azotobacter
4. Nitrosomonas
Anabaena is associated with Azolla's:
1. Stem
2. Leaves
3. Roots
4. Flowers
Nitrogen-fixing bacteria converts:
1.
2.
3.
4.
An aquatic fern that is used to increase the yield of paddy crops:
1. Azolla
2. Salvinia
3. Marsilea
4. Isoetes
Enzyme first used for nitrogen fixation:
1. Nitrogenase
2. Nitroreductase
3. Transferase
4. Transaminase
Which aquatic fern performs nitrogen fixation:
1. Azolla
2. Nostoc
3. Salvia
4. Salvinia
If by radiation all nitrogenase enzymes are inactivated, then there will be no:
1. Fixation of atmospheric nitrogen
2. Conversion from nitrate to nitrite in legumes
3. Conversion from ammonium to nitrate in soil
4. Fixation of nitrogen in legumes
All of the following statements concerning the Actinomycetous filamentous soil bacterium Frankia are correct EXCEPT that Frankia:
1. | Forms specialized vesicles in which the nitrogenase is protected from oxygen by a chemical barrier involving triterpene hopanoids |
2. | Can induce root nodules on many plant species |
3. | Like Rhizobium, it usually infects its host plant through root hair deformation and stimulates cell proliferation in the host's cortex |
4. | Cannot fix nitrogen in the free-living state |