Plants that have symbiotic relations with nitrogen-fixing bacteria provide the bacteria with:

Options

A. nitrogen
B. sugars
C. nitrites
D. enzymes

Answer

To answer the question regarding what plants that have symbiotic relationships with nitrogen-fixing bacteria provide to the bacteria, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Symbiotic Relationships**:
- A symbiotic relationship is a mutualistic interaction between two different organisms where both benefit from each other.

2. **Identify the Organisms Involved**:
- In this case, the two organisms are leguminous plants and nitrogen-fixing bacteria (such as Rhizobium).

3. **Location of Interaction**:
- The nitrogen-fixing bacteria typically reside in the root nodules of leguminous plants.

4. **Function of Nitrogen-Fixing Bacteria**:
- These bacteria convert atmospheric nitrogen (N2) into a form that plants can use, such as ammonia (NH3), which is essential for plant growth.

5. **What Plants Provide to Bacteria**:
- During photosynthesis, plants produce sugars (like glucose) which are essential for energy. In this mutual relationship, the plants provide these sugars to the bacteria.

6. **Conclusion**:
- Thus, the correct answer to the question is that plants provide the bacteria with sugars.

### Final Answer:
Plants that have symbiotic relationships with nitrogen-fixing bacteria provide the bacteria with **sugar**.

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