Conversion of nitrate to nitrogen gas and nitrous oxide is called:

(1) nitrogen fixation

(2) ammonification

(3) denitrification

(4) eutrophication

Which of the following minerals required by a plant is not a ‘macronutrient’?
1. Iron
2. Sulfur
3. Potassium
4. Calcium

Match each item in Column I with one in Column II and select the best match from the codes given:

    Codes:

Match each item in Column I with one in Column II and select the best match from the codes given:

    Codes:

Consider the two statements:
I. Excess of manganese in plants may induce deficiencies of iron, magnesium and calcium.
II. Manganese inhibits translocation of iron and magnesium at apex and competes with calcium for uptake.
1. Both I and II are correct and II explains I
2. Both I and II are correct but II does not explain I
3. I is correct and II is incorrect
4. Both I and II are incorrect

Nitrogen fixing bacteria live in the nodules in a plant root. These nodules are formed by the cells of:
1. Epidermis
2. Cortex
3. Endodermis
4. Vascular cylinder

For each NH₃ produced, the number of ATP molecules required by the nitrogenase enzyme is:
1. 4
2. 8
3. 12
4. 16

Identify the incorrect statement:
1. Frankia does not produce nitrogen-fixing nodules on the roots of non-leguminous plants
2. Microbes like Rhizobium live as aerobes under free living condition and become anaerobic during nitrogen fixing events
3. Nitrogenase is a Mo-Fe protein
4. Azotobacter and Beijernickia are free-living are free living nitrogen-fixing aerobic microbes.

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

Match the following concerning essential elements and their functions in plants: