1. convert free nitrogen to nitrogen compounds
2. convert proteins into ammonia
3. reduce nitrates to free nitrogen
4. oxidize ammonia to nitrates
Which one of the following is not a micronutrient?
1. Molybdenum
2. Magnesium
3. Zinc
4. Boron
The free-living, anaerobic nitrogen-fixer is:
1. Beijerinckia
2. Rhodospirillum
3. Rhizobium
4. Azotobacter
Manganese is required in:
1. nucleic acid synthesis
2. plant cell wall formation
3. photolysis of water during photosynthesis
4. chlorophyll synthesis
Which of the following is a symbiotic nitrogen fixer?
1. Glomus
2. Azotobacter
3. Frankia
4. Azolla
1. | Bradyrhizobium | 2. | Clostridium |
3. | Frankia | 4. | Azorhizobium |
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
About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and:
1. phosphorus and sulphur
2. sulphur and magnesium
3. magnesium and sodium
4. calcium and phosphorus
Which one of the following elements is not an essential micronutrient for plant growth?
1. Mn
2. Zn
3. Cu
4. Ca
A plant requires magnesium for:
1. holding cells together
2. protein synthesis
3. chlorophyll synthesis
4. cell wall development