Vascular bundle is closed when

Options

A. cambium present
B. cambium absent
C. pericycle absent
D. none of these

Answer

**Step-by-Step Solution:**

1. **Understanding Vascular Bundles**: Vascular bundles are structures in plants that contain the xylem and phloem, which are responsible for the transport of water, nutrients, and food.

2. **Definition of Closed Vascular Bundles**: A closed vascular bundle is characterized by the absence of cambium between the xylem and phloem. Cambium is a type of meristematic tissue responsible for secondary growth.

3. **Absence of Cambium**: In closed vascular bundles, there is no inter-fascicular cambium. This means that there is direct contact between the xylem and phloem, and they do not have the ability to form secondary xylem or phloem.

4. **Examples of Closed Vascular Bundles**: Closed vascular bundles are typically found in monocots (like grasses) and certain other plants. In these plants, the vascular bundles are usually scattered throughout the stem.

5. **Conclusion**: Therefore, a vascular bundle is considered closed when there is no cambium present between the xylem and phloem, leading to the direct contact of these two tissues.

**Final Answer**: A vascular bundle is closed when there is no cambium present between xylem and phloem.

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