Vascular bundles in monocotyledons are considered closed because :

Options

A. cambium is absent
B. there is surronded all perforations
C. xylem is surrounded all around by phelom
D. a bundle sheath surround each nudle

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. **Definition of Cambium**: Cambium is a layer of actively dividing cells located between the xylem and phloem. It plays a crucial role in the growth of plants.

3. **Types of Vascular Bundles**: There are two types of vascular bundles based on the presence or absence of cambium:
- **Open Vascular Bundles**: These contain cambium, allowing for secondary growth (growth in thickness).
- **Closed Vascular Bundles**: These lack cambium, which means they do not undergo secondary growth.

4. **Characteristics of Monocotyledons**: Monocots, or monocotyledons, are a group of flowering plants that typically have closed vascular bundles. This means that in monocots, the xylem and phloem do not have the cambium layer between them.

5. **Conclusion**: The vascular bundles in monocotyledons are considered closed because they do not have cambium, preventing secondary growth.

**Final Answer**: Vascular bundles in monocotyledons are considered closed because of the absence of cambium.

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