(Out of current syllabus — rationalised out of NCERT; included as it was asked in earlier NEET papers) Which one of the following will accelerate phosphorus cycle?
Answer: (C) Weathering of rocks. Answer: (C) (Out of current syllabus — rationalised out; last asked ≤2023) Phosphorus moves through a sedimentary biogeochemical cycle whose main reservoir is rock and sediment, with no significant gaseous (atmospheric) phase.
- A.Burning of fossil fuels
- B.Volcanic activity
- C.Weathering of rocks✓
- D.Rainfall and storms
Correct Answer
(C) Weathering of rocks
Solution & Explanation
Answer: (C) (Out of current syllabus — rationalised out; last asked ≤2023) Phosphorus moves through a sedimentary biogeochemical cycle whose main reservoir is rock and sediment, with no significant gaseous (atmospheric) phase. Weathering of phosphate-bearing rocks releases phosphate ions into soil and water, making them available to producers, so weathering is what accelerates the phosphorus cycle. Burning of fossil fuels, volcanic activity and rainfall/storms drive atmospheric/gaseous cycles (like carbon or sulphur) and have little direct effect on the phosphorus reservoir. NCERT Reference: Class XII, Ecosystem — phosphorus cycle (pre-2023 NCERT; rationalised out of current reprint).