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

1. Leghaemoglobin

2. Xanthophylls

3. Carotene

4. Cytochrome

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

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

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

What type of reaction is shown in the given figure?


1. Deamination
2. Reductive amination
3. Transamination
4. Nitrogenation

Consider the following statements:
Regarding plant mineral nutrition -
I. The deficiency symptoms of nitrogen, potassium and magnesium are visible first in senescent leaves.
II. Manganese inhibits calcium translocation in shoot apex.
III. Lack or low level of N, K, S, Mo causes an inhibition of cell division.
Which of the above statements are true?
1. I and II only           2. I and III only
3. II and III only         4. I, II, and III