In a dorsiventral leaf, what is true regarding the position of xylem?

Options

A. Xylmen is towards adaxial epidermis
B. Xylem is towards abaxial epidermis
C. Xylem surrounds phloem.
D. Xylem is surrounded by phloem

Answer

### Step-by-Step Solution:

1. **Understanding Dorsiventral Leaves**:
- Dorsiventral leaves have distinct upper (adaxial) and lower (abaxial) surfaces. The upper surface is typically more exposed to sunlight, while the lower surface is often shaded.

2. **Identifying the Structure of the Leaf**:
- In a dorsiventral leaf, the mesophyll tissue is differentiated into two types: the upper palisade parenchyma and the lower spongy parenchyma. The palisade parenchyma is tightly packed and rich in chloroplasts, while the spongy parenchyma has air spaces for gas exchange.

3. **Position of Vascular Bundles**:
- Vascular bundles, which contain xylem and phloem, are located in the middle of the leaf. In a typical dorsiventral leaf, the xylem is positioned above the phloem.

4. **Determining the Position of Xylem**:
- Since the xylem is located on the upper side of the vascular bundle, it is closer to the adaxial epidermis (the upper surface of the leaf).

5. **Conclusion**:
- Therefore, in a dorsiventral leaf, the correct statement regarding the position of xylem is that "xylem is towards the adaxial epidermis."