Nitrogen-fixing bacteria converts:
1. $N_2$ $\to$ $N{H}_3$
2. $N{H}_4^{+}$ $\to$ $Nitrates$
3. $N{O}_2$ $\to$ $N{O}_3$
4. $N{O}_3$ $\to$ $N_2$

Plants take zinc in the form of:

The major role of minor elements inside living organisms is to act as:
1. Co-factors of enzymes
2. Building blocks of important amino acids
3. Constituent of hormones
4. Binder of cell structure

Which element is located at the center of the porphyrin ring in chlorophyll?

Which one of the following mineral elements plays an important role in biological nitrogen fixation:
1. Copper
2. Manganese
3. Zinc
4. Molybdenum

Boron in green plants assists in:
1. Activation of enzymes
2. Acting of enzyme cofactor
3. Photosynthesis
4. Sugar transport

Enzyme first used for nitrogen fixation:
1.  Nitrogenase
2.  Nitroreductase
3.  Transferase
4.  Transaminase

Cytochrome is:
1.  Metallo flavo protein
2.  Fe containing porphyrin pigment
3.  Glycoprotein
4.  Lipid

Roots of which plant contains a pink pigment that has an affinity for oxygen:
1.  Carrot
2.  Soyabean
3.  Mustard
4.  Radish

If by radiation all nitrogenase enzymes are inactivated, then there will be no:
1. Fixation of atmospheric nitrogen
2. Conversion from nitrate to nitrite in legumes
3. Conversion from ammonium to nitrate in soil
4. Fixation of nitrogen in legumes