Q. No.For its action, nitrogenase requires:
1. Light
2. Mn2+
3. Super oxygen radicals
4. High input of energy
1. Light
2. Mn2+
3. Super oxygen radicals
4. High input of energy
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
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 |
Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation:
| 1. | Nodules act as sites for nitrogen fixation |
| 2. | The enzyme nitrogenase catalyses the conversion of atmospheric N2 to NH3 |
| 3. | Nitrogenase is insensitive to oxygen |
| 4. | Leghaemoglobin scavenges oxygen and is pinkish in colour |
Which one of the following is essential for the photolysis of water?
1. Boron
2. Manganese
3. Zinc
4. Copper
Which one of the following is not an essential mineral element for plants while the remaining three are?
1. Phosphorus
2. Iron
3. Manganese
4. Cadmium
1. Magnesium
2. Calcium
3. Phosphorus
4. Sulphur
| 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 |
Sulphur is an important nutrient for optimum growth and productivity in:
1. pulse crops
2. cereals
3. fibre crops
4. oilseed crops
Farmers in a particular region were concerned that pre-mature yellowing of leaves of a pulse crop might cause a decrease in the yield. Which treatment could be most beneficial to obtain maximum seed yield?
| 1. | Frequent irrigation of the crop |
| 2. | Treatment of the paints with cytokinins along with a small dose of nitrogenous fertilizer |
| 3. | Removal of all yellow leaves and spraying the remaining green leaves with 2,4,5-trichlorophenoxy acetic acid |
| 4. | Application of iron and magnesium to promote the synthesis of chlorophyll |
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