Excessive use of fertilizers often leads to the accumulation of nitrates in water. When this water is utilized by animals, these nitrates,

Options

A. are converted into non-toxic nitrites by intestinal bacteria
B. are converted into toxic nitrites by intestinal bacteria
C. get deposited in the intestine
D. none of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Context**: The question discusses the impact of excessive fertilizer use, which leads to the accumulation of nitrates in water sources. This is a common environmental issue, particularly in agricultural areas.

2. **Identifying the Problem**: When animals consume water that contains high levels of nitrates, it can have adverse effects on their health. The question specifically asks what happens to these nitrates in the animals' bodies.

3. **Role of Intestinal Bacteria**: Animals have intestinal bacteria that aid in digestion. These bacteria can interact with various substances, including nitrates.

4. **Conversion of Nitrates**: The key point is that when animals ingest water with high nitrate levels, the intestinal bacteria can convert these nitrates. The question provides options regarding the nature of this conversion.

5. **Evaluating the Options**:
- **Option 1**: Converted into nontoxic nitrates by intestinal bacteria - This is incorrect, as nitrates can become toxic.
- **Option 2**: Converted into toxic nitrates by intestinal bacteria - This is correct, as the bacteria can convert nitrates into forms that are harmful.
- **Option 3**: Get deposited into the intestine - This is not the primary concern; the conversion is more relevant.
- **Option 4**: None of the above - This is incorrect since option 2 is valid.

6. **Conclusion**: Based on the understanding of how nitrates interact with intestinal bacteria in animals, the correct answer is that nitrates are converted into toxic nitrates by intestinal bacteria.

**Final Answer**: The correct option is **converted into toxic nitrates by intestinal bacteria**.

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