Ureides have

Options

A. high N/C ratio
B. low N/C ratio
C. high `NH _2//C` ratio
D. low `NH _2//C` ratio

Answer

To solve the question "Ureides have," we need to analyze the information provided and determine the correct option based on our understanding of ureides and their characteristics.

### Step-by-Step Solution:

1. **Understanding Ureides**:
- Ureides are nitrogen-containing compounds that are derived from urea. They are significant in the nitrogen metabolism of plants, particularly in leguminous plants.

2. **Nitrogen Fixation in Plants**:
- Leguminous plants, such as soybeans, have the ability to fix atmospheric nitrogen. This process is crucial for their growth and development as it allows them to assimilate nitrogen from the atmosphere.

3. **Transport Mechanism**:
- Ureides are transported through the xylem of plants to the shoots. This transport is essential for the distribution of nitrogen throughout the plant.

4. **Chemical Composition**:
- The chemical structure of ureides is similar to that of urea. Urea has the formula NH2-CO-NH2, and ureides can be found in forms such as allantoin and allantoic acid.

5. **Nitrogen to Carbon Ratio**:
- Ureides typically have a high nitrogen to carbon ratio, which is an important characteristic that distinguishes them from other nitrogen compounds.

6. **Identifying the Correct Option**:
- Based on the information gathered, we can conclude that ureides are characterized by their high nitrogen content and their forms (like allantoin and allantoic acid). Therefore, the correct option regarding ureides would be the one that reflects these characteristics.

### Conclusion:
- The correct answer to the question "Ureides have" is that they are nitrogen-rich compounds found in leguminous plants, often in the forms of allantoin and allantoic acid.