Which of the following statements is true?

• A. Unlike nitrogen, carbon, and water, the atmosphere is not a significant reservoir of phosphorus.
• B. Sedimentary rock is one of the largest reservoirs of phosphorus.
• C. Phosphorus is essential to ecosystems as it’s a major component of nucleic acids & ATP.
• D. All of the above are true.

Answer: (D)

Verified step by step guidance

1. Understand the role of phosphorus in ecosystems: Phosphorus is a crucial element for living organisms as it is a key component of nucleic acids (DNA and RNA) and ATP (adenosine triphosphate), which is essential for energy transfer within cells.
2. Identify the reservoirs of phosphorus: Unlike nitrogen, carbon, and water, phosphorus does not have a significant atmospheric component. Instead, it is primarily found in sedimentary rocks, making these rocks one of the largest reservoirs of phosphorus.
3. Compare phosphorus with other elements: Nitrogen and carbon have significant atmospheric cycles, whereas phosphorus is mainly cycled through the lithosphere and biosphere, with minimal atmospheric presence.
4. Evaluate the statements: Each statement provided in the problem highlights a different aspect of phosphorus's role and presence in the environment. All statements are consistent with the known characteristics of phosphorus.
5. Conclude the analysis: Based on the understanding of phosphorus's role in ecosystems, its reservoirs, and its comparison with other elements, all the statements provided are true.