During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by?
1. Leghaemoglobin
2. Xanthophylls
3. Carotene
4. Cytochrome
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
The function of leghemoglobin in the root nodules of legumes is:
1. oxygen removal
2. nodule differentiation
3. expression of nif gene
4. inhibition of nitrogenase activity
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 |