Root differs from stem in having

Options

A. Parenchymatous cortex
B. Pith
C. Exarch xylem
D. Pericycle

Answer

To answer the question "Root differs from stem in having," we need to analyze the structural differences between roots and stems. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding the Structure of Roots and Stems**:
- Roots and stems are two essential parts of a plant, each with distinct structures and functions. Roots primarily anchor the plant and absorb water and nutrients, while stems support the plant and transport materials.

2. **Identifying Key Differences**:
- One of the main differences between roots and stems lies in the arrangement of vascular tissues, specifically xylem.

3. **Xylem Arrangement**:
- In roots, the xylem is typically arranged in an **exarch** condition. This means that the protoxylem (the first-formed xylem) is located towards the outer side, while the metaxylem (the later-formed xylem) is located towards the center.
- In contrast, in stems, the xylem is arranged in an **endarch** condition. Here, the protoxylem is located towards the center, and the metaxylem is towards the outer side.

4. **Conclusion**:
- Therefore, the key difference between roots and stems is that roots have exarch xylem, while stems have endarch xylem.

### Final Answer:
Roots differ from stems in having **exarch xylem**.

---