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

During biological nitrogen fixation, inactivation of nitrogenase by oxygen poisoning is prevented by?

1. Leghaemoglobin

2. Xanthophylls

3. Carotene

4. Cytochrome

Boron in green plants assists in
1. activation of enzymes
2. acting as enzyme cofactor
3. photosynthesis
4. sugar transport

Which of the following is an amide involved in nitrogen metabolism by plants?

1. Methionine

2. Cysteine

3. Serine

4. Asparagine

Study the cycle shown below and select the option which gives correct words for all the four blanks A, B, C and D –

Plant prefers to absorb nitrogen in form of nitrate from
soil, then it is reduced to ammonia. This reduction to
ammonia takes place in which part of plant
1. Root.
2. Leaf.
3. Stem.
4. Any

Reaction of N₂ fixation process is depicted below

$N_2+\left[A\right]+\left[B\right]+16<mspace\; width="1em"></mspace>ATP\to$
$2N{H}_3+\left[C\right]+16ADP+16<mspace\; width="1em"></mspace>Pi$

Select the correct set of A,B and C

1. A = $8{\mathrm{e}}^{-}$, B=$8{\mathrm{H}}^{+}$; C = ${\mathrm{H}}_2$

2.  A = ${\mathrm{H}}_2$, B=$8{\mathrm{e}}^{-}$; C = $8{\mathrm{H}}^{+}$

3. A = $8{\mathrm{e}}^{-}$, B=${\mathrm{H}}_2$; C = $8{\mathrm{H}}^{+}$

4. A = $8{\mathrm{H}}^{+}$, B=${\mathrm{H}}_2$; C = $8{\mathrm{e}}^{-}$

Which of the following bacteria reduce nitrate in soil into nitrogen?

1. Nitrobacter

2. Thiobacillus

3. Nitrococcus

4. Nitrosomonas

In the given diagram of a typical set up for nutrient solution culture, the purpose of X is:

1. Addition of water 2. Addition of nutrients 3. Removal of wastes 4. Aeration