Q. No.During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by?
1. Leghaemoglobin
2. Xanthophylls
3. Carotene
4. Cytochrome
Minerals known to be required in large amounts for plant growth include:
1. phosphorus, potassium, sulphur, calcium
2. calcium, magnesium, manganese, copper
3. potassium, phosphorus, selenium, boron
4. magnesium, sulphur, iron, zinc
Deficiency symptoms of nitrogen and potassium are visible first in:
1. Senescent leaves
2. Young leaves
3. Roots
4. Buds
2. Nitrite
3. Glutamate
4.
| 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 |
Best defined function of manganese in green plants is :
1. Photolysis of water
2. Calvin cycle
3. Nitrogen fixation
4. Water absorption
Which one of the following is a wrong statement?
| 1. | Anabaena and Nostoc are capable of fixing nitrogen in a free-living state also |
| 2. | Root nodule-forming nitrogen fixers live as aerobes under free-living conditions |
| 3. | Phosphorus is a constituent of cell membranes, certain nucleic acids, and all proteins |
| 4. | Nitrosomonas and Nitrobacter are chemoautotrophs |
For its action, nitrogenase requires:
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
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