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

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

The most abundant element present in the plant is:

1. Nitrogen

2. Manganese

3. Iron

4. Carbon 

A nutritionally wild type organism, which does not require any additional growth supplement is known as:

1. Holotype

2. Auxotroph

3. Prototroph

4. Phenotype 

Anabaena is associated with Azolla's:
1.  Stem
2.  Leaves
3.  Roots
4.  Flowers

Which of the following does not contain metal:
1.  Glycoproteins
2.  Ferritin
3.  Cytochromes
4.  Chromoproteins

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. $N{O}_3$ $\to$ $N_2$

Insectivorous plants grow in the soil which is deficient in:
1.  Mg
2.  Ca
3.  P
4.  N

When the plants are grown in magnesium-deficient but urea-rich soil, the symptoms expressed are:

1. Yellowish leaves

2. Colourless petiole

3. Dark green leaves

4. Shoot apex die

Plants take zinc in the form of: