Q. Consider the following statements regarding the Phosphorus Cycle:
1. Phosphorous has a vital role in cell development.
2. Rocks release phosphate ions when in contact with rainwater.
Which of the statements given above is/are correct?
Answer: C
Notes:
Phosphorus Cycle
- Phosphorus is an element that can be found in several compound forms in water, soil, and sediments.
- It is an essential nutrient needed for the growth of plants and animals as well.
- It has a vital role in cell development and is a key component of molecules that store energy.
- Phosphorus occurs in nature as the phosphate ion.
- In addition to phosphate runoff as a result of human activity, natural surface runoff also takes place. It is leached from phosphate-containing rock by weathering, thus sending phosphates into rivers, lakes, and the ocean. This rock has its origins in the ocean.
- Rocks when in contact with rainwater, release phosphate ions and other minerals over time.
- This inorganic phosphate is then distributed in soils and water.
- Plants then take up inorganic phosphate from the soil, and these plants may then be consumed by animals.
- The phosphate is then incorporated into organic molecules such as DNA, and when plants or animals die and decay, the organic phosphate is returned to the soil.
- Bacteria in the soil then breaks down the organic matter into forms of phosphate that are absorbable by plants. It is also a process called mineralisation.
- Phosphorus in the soil can then end up in waterways and oceans and can be incorporated into sediments over time.
Source: NCERT