Question

Which among the following do not return to nutrients?

• A. Calcium
• B. Nitrogen
• C. Phosphorus
• D. Magnesium

Answer 1

The correct option is B

Nitrogen

The correct option is B.

Explanation of correct option:

1. Nitrogen goes back to the soil.
2. The major source of free nitrogen is the action of soil micro-organisms and associated plant roots on atmospheric nitrogen found in pore spaces of the soil.
3. When animals and plants die, the denitrifying bacteria present in the soil, convert the organic matter back into ammonium.
4. This process of decomposition produces ammonia, which is further used for other biological processes.

Explanation of incorrect option:

Option A:

1. Calcium is required for normal root system development.
2. Calcium is in charge of holding plant cell walls together.
3. It is also necessary for the activation of enzymes in plants
4. It plays important role in the transmission of signals that coordinate cellular functions.
5. Calcium is an immobile macronutrient.
6. It is mainly gathered at the roots and deficiency is not frequent.

Option C:

1. Phosphorus is a macronutrient that is a component of ATP.
2. It is absorbed by plants as phosphate ions.
3. Phosphorus is critical for plant growth and productivity.
4. It contributes to photosynthesis, respiration, and nitrogen fixation.

Option D:

1. Magnesium is an important element in the compound chlorophyll.
2. Magnesium is also important in phosphate metabolism.
3. Magnesium is essential in the process of cell division.
4. It helps in the formation of proteins.

Final answer: Nitrogen does not return to nutrients.