In leaves, the vascular bundles are

Options

A. Bicollateral & open
B. Collateral & open
C. Collateral & closed
D. Radial & exarch

Answer

To answer the question "In leaves, the vascular bundles are...", we will break down the information provided in the video transcript into a step-by-step solution.

### Step-by-Step Solution:

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

2. **Location in Leaves**:
- In leaves, vascular bundles are located within the veins. They play a crucial role in the leaf's functions, such as photosynthesis and transpiration.

3. **Type of Vascular Bundles**:
- The vascular bundles in leaves are classified as "closed type." This means they lack vascular cambium, which is a type of meristematic tissue that allows for secondary growth.

4. **Characteristics of Closed Vascular Bundles**:
- Since the vascular cambium is absent, the vascular bundles do not have the ability to grow in thickness. This leads to the classification of these bundles as closed.

5. **Arrangement in Leaves**:
- The vascular bundles are typically found in a scattered arrangement within the mesophyll of the leaves. The midrib of the leaf contains larger vascular bundles.

6. **Shape and Structure**:
- Each vascular bundle is surrounded by barrel-shaped parenchyma cells that cover the xylem and phloem. This arrangement forms what is known as a conjoined collateral vascular bundle.

7. **Conclusion**:
- Based on the characteristics discussed, the correct answer is that in leaves, the vascular bundles are "collateral and closed."

### Final Answer:
In leaves, the vascular bundles are collateral and closed.