When a leaf trace extends from a vascular bundle in a dicot stem, what would be the arrangement of vascular tissues in the veins of the leaf ?

Options

A. Xylem would be on top and the phloem on the bottom
B. Phloem would be on top and the xylem on the bottom
C. Xylem would encircle the phloem
D. Phloem would encircle the xylem

Explanation

To determine the arrangement of vascular tissues in the veins of a leaf when a leaf trace extends from a vascular bundle in a dicot stem, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Leaf Trace**: A leaf trace is a strand of vascular tissue that extends from the vascular bundle in the stem to the leaf. This is crucial for the transport of water, nutrients, and food.

2. **Identifying Vascular Bundles**: In dicot plants, vascular bundles are arranged in a specific manner. In the stem, the xylem is typically located towards the inside (center) of the stem, while the phloem is located towards the outside.

3. **Analyzing Leaf Structure**: In a dicot leaf, the arrangement of vascular tissues follows a similar pattern. The leaf has a reticulate (net-like) venation pattern, which means the veins form a network.

4. **Position of Xylem and Phloem**: When examining a cross-section of a dicot leaf, we observe that the xylem is positioned on the upper side (adaxial side) of the vascular bundle, while the phloem is located on the lower side (abaxial side).

5. **Conclusion**: Based on this arrangement, we conclude that when a leaf trace extends from a vascular bundle in a dicot stem, the xylem would be on top and the phloem would be on the bottom.

### Final Answer:
The correct arrangement of vascular tissues in the veins of the leaf is: **Xylem on top and Phloem on the bottom** (Option 1).

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