Thiobacillus is a group of bacteria helpful in carrying out:
1. Denitrification
2. Nitrogen fixation
3. Chemoautotrophic fixation
4. Nitrification
A plant requires magnesium (Mg) for:
1. holding cells together
2. protein synthesis
3. chlorophyll synthesis
4. cell wall development
Which of the following is responsible for biological nitrogen fixation?
1. Nif gene
2. Nitrogenase
3. Both 1. and 2.
4. RNA synthetase
Which of the following is a non-symbiotic nitrogen fixer organism?
1. VAM
2. Azotobacter
3. Anabaena
4. Rhizobium
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
1. | Bradyrhizobium | 2. | Clostridium |
3. | Frankia | 4. | Azorhizobium |
Manganese is required in:
1. nucleic acid synthesis
2. plant cell wall formation
3. photolysis of water during photosynthesis
4. chlorophyll synthesis
During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by?
1. Leghaemoglobin
2. Xanthophylls
3. Carotene
4. Cytochrome