Which is correct

Options

A. Legumes fix nitrogen through bacteria in their leaves
B. Legumes fix nitrogen through bacteria in their roots
C. Legumes fix nitrogen independent of bacteria
D. Legumes do not fix nitrogen

Explanation

To determine which statement is correct regarding nitrogen fixation in legumes, let's analyze the information step by step.

### Step-by-Step Solution:

1. **Understanding Legumes**: Legumes are a group of plants that belong to the family Fabaceae. They are known for their ability to fix nitrogen, which is essential for plant growth.

2. **Role of Rhizobium**: The process of nitrogen fixation in legumes is primarily facilitated by a type of bacteria known as Rhizobium. These bacteria form a symbiotic relationship with the roots of leguminous plants.

3. **Infection of Roots**: The Rhizobium bacteria infect the roots of leguminous plants. This infection leads to the formation of specialized structures called root nodules.

4. **Formation of Root Nodules**: Root nodules are small, rounded structures that develop on the roots of legumes. Inside these nodules, Rhizobium bacteria convert atmospheric nitrogen (N₂) into ammonia (NH₃), which is a usable form of nitrogen for the plant.

5. **Nitrogen Fixation Process**: The process of converting atmospheric nitrogen into ammonia is known as nitrogen fixation. This is crucial because most plants cannot utilize atmospheric nitrogen directly.

6. **Correct Statement**: Based on the information analyzed, the correct statement is: "Legumes fix nitrogen through bacteria in their roots." This is because the Rhizobium bacteria reside in the root nodules, not in the leaves.

### Conclusion:
The correct statement regarding nitrogen fixation in legumes is that they fix nitrogen through bacteria (Rhizobium) in their roots.

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