A plant requires magnesium for

Which of the following element helps in maintaining the structure of ribosomes?

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

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

The product(s) of the reaction catalyzed by nitrogenase in root nodules of leguminous plants is/are.
1. Nitrate alone
2. Ammonia and oxygen
3. Ammonia and hydrogen
4. Ammonia alone

Which of the following is a non–symbiotic nitrogen fixing bacteria?
1.  Rhizobium
2.  Mycorrhiza
3.  Azotobacter
4.  Nitrosomonas

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. $N{O}_3$ $\to$ $N_2$

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

Select the mismatch:

1. Rhodospirillum - Mycorrhiza

2. Anabaena - Nitrogen fixer

3. Rhizobium - Alfalfa

4. Frankia - Alnus