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Which of the following statements about eutrophication is/are correct?
(i)It increases the amount of sunlight reaching to the bottom of the water body.
(ii)It occurs due to excessive nutrient enrichment in water of the river and lakes.
(iii) It results in decrease in water clarity, dissolved oxygen and aquatic life.

A

(ii) only

B

(i) and (iii) only

C

(ii) and (iii) only

D

(i), (ii) and (iii)

Text Solution

AI Generated Solution

The correct Answer is:
To determine which statements about eutrophication are correct, let's analyze each statement step by step. ### Step 1: Analyze Statement (i) **Statement (i)**: "It increases the amount of sunlight reaching to the bottom of the water body." - **Explanation**: Eutrophication often leads to an increase in algae and aquatic plants due to nutrient enrichment. These organisms can block sunlight from penetrating deeper into the water body. As a result, the amount of sunlight reaching the bottom decreases rather than increases. **Conclusion**: This statement is **incorrect**. ### Step 2: Analyze Statement (ii) **Statement (ii)**: "It occurs due to excessive nutrient enrichment in water of the river and lakes." - **Explanation**: Eutrophication is primarily caused by an excess of nutrients, particularly nitrogen and phosphorus, which often come from agricultural runoff, sewage discharge, and other sources. This nutrient enrichment leads to the rapid growth of algae and other aquatic plants. **Conclusion**: This statement is **correct**. ### Step 3: Analyze Statement (iii) **Statement (iii)**: "It results in decrease in water clarity, dissolved oxygen and aquatic life." - **Explanation**: As algae bloom due to nutrient enrichment, water clarity decreases because of the increased biomass. When the algae die, their decomposition consumes a significant amount of dissolved oxygen, leading to hypoxic conditions (low oxygen levels). This can result in the death of fish and other aquatic organisms, thereby decreasing aquatic life. **Conclusion**: This statement is **correct**. ### Final Conclusion: Based on the analysis: - Statement (i) is incorrect. - Statement (ii) is correct. - Statement (iii) is correct. Thus, the correct statements about eutrophication are **(ii) and (iii)**.
To determine which statements about eutrophication are correct, let's analyze each statement step by step. ### Step 1: Analyze Statement (i) **Statement (i)**: "It increases the amount of sunlight reaching to the bottom of the water body." - **Explanation**: Eutrophication often leads to an increase in algae and aquatic plants due to nutrient enrichment. These organisms can block sunlight from penetrating deeper into the water body. As a result, the amount of sunlight reaching the bottom decreases rather than increases. **Conclusion**: This statement is **incorrect**. ...
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