Question

In most of terrestrial lakes, phosphorous is a limiting nutrient. Phosphorous is not an essential nutrient but present in high amounts compared to other nutrients. Which of the following is most appropriate?

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

Phosphorus is an essential nutrient and is present in low amounts in most freshwater lakes, making it the limiting nutrient.

Answer 1

The Correct Option is C

Step 1: Concept
Limiting nutrients in aquatic ecosystems.

Step 2: Meaning
A limiting nutrient is one whose scarcity most restricts primary production. Phosphorus is indeed essential for life.

Step 3: Analysis
Statement (A) is correct: phosphorus is a limiting nutrient in most terrestrial lakes.
Statement (R) is incorrect: phosphorus is an essential nutrient (for ATP, DNA, cell membranes), and it is typically present in low amounts in lakes (which is why it is limiting), not high amounts.

Step 4: Conclusion
(A) is correct but (R) is not correct. Final Answer: (C)