Closed vascular bundles lack

Options

A. conjunctive tissue
B. cambium
C. pith
D. ground tissue

Answer

**Step-by-Step Solution:**

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

2. **Types of Vascular Bundles**: There are two main types of vascular bundles: open and closed.
- **Open Vascular Bundles**: These contain a layer of cambium between the xylem and phloem. Cambium is a type of meristematic tissue that allows for secondary growth in plants.
- **Closed Vascular Bundles**: These lack cambium, meaning there is no layer between the xylem and phloem.

3. **Role of Cambium**: Cambium is responsible for secondary growth, which increases the thickness of stems and roots. In plants where cambium is present, secondary growth can occur.

4. **Implications of Closed Vascular Bundles**: Since closed vascular bundles do not have cambium, they cannot undergo secondary growth. This characteristic is typical of monocots (monocotyledons), such as grasses.

5. **Conclusion**: Therefore, closed vascular bundles lack cambium, which is the key feature that differentiates them from open vascular bundles.

**Final Answer**: Closed vascular bundles lack cambium.

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