Study the cycle shown below and select the option which gives the correct words for all four blanks A, B, C, and D:

   

 Options:

	A	B	C	D
1.	Denitrification	Ammonification	Plants	Animals
2.	Nitrification	Denitrification	Animals	Plants
3.	Denitrification	Nitrification	Plants	Animals
4.	Nitrification	Ammonification	Animals	Plants

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

1. Magnesium

2. Zinc

3. Copper

4. Molybdenum

In Glycine max, the product of biological nitrogen fixation is transported from the root nodules to other parts as:

1. Ammonia

2. Glutamate

3. Nitrates

4. Ureides

Match Column-I with Column- II.
 

Choose the correct answer from the options given below:

Mark the correct option with respect to hydroponics

1. It can avoid problem of soil borne pathogens

2. It avoids problem of weeding

3. Out of season vegetables and flowers can be obtained

4. all of these

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

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

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.

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

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