Phosphorus cycle Knowledge-Based Practice

Questions

1. 1.

   During the biological recycling phase of the terrestrial phosphorus cycle, which process converts organic phosphorus found in plant detritus and animal waste back into bioavailable inorganic phosphate ions?

   • A) Biological assimilation
   • B) Microbial mineralization
   • C) Chemical weathering
   • D) Geological sedimentation
2. 2.

   In the global phosphorus cycle, which process is primarily responsible for removing phosphorus from the active biological pool and sequestering it into the long-term geological reservoir?

   • A) Evaporative volatilization of dissolved phosphorus into atmospheric gas
   • B) Chemosynthetic assimilation by deep-sea benthic archaebacteria
   • C) Sedimentation and deposition of insoluble phosphates and organic detritus onto the ocean floor
   • D) Leaching and subterranean percolation of dissolved ions back into terrestrial topsoils
3. 3.

   During the biological phase of the phosphorus cycle, primary producers absorb dissolved phosphate ions from the soil or water. Which of the following pairs of cellular components directly requires this assimilated phosphorus for their synthesis?

   • A) Triglycerides and glycogen
   • B) Polypeptides and cellulose
   • C) Nucleic acids and phospholipids
   • D) Monosaccharides and fibrous proteins
4. 4.

   Which natural process is primarily responsible for releasing inorganic phosphate into soil and aquatic environments from Earth's main geological reservoir?

   • A) Microbial fixation of volatile phosphorus compounds
   • B) Direct precipitation of gaseous phosphorus from the atmosphere
   • C) Photochemical oxidation of elemental phosphorus in the troposphere
   • D) Weathering and chemical breakdown of phosphate-bearing rocks
5. 5.

   Which of the following characteristics distinguishes the global phosphorus cycle from the carbon and nitrogen cycles?

   • A) It relies primarily on specialized prokaryotes to fix atmospheric compounds into organic molecules.
   • B) Its largest active reservoir of matter is located within the upper troposphere.
   • C) It lacks a significant gaseous or atmospheric reservoir under normal environmental conditions.
   • D) It depends on high-energy lightning discharges to deposit bioavailable minerals into terrestrial soils.

Answers and step-by-step solutions appear after you finish the test.