Vascular bundles in a dicot leaf are

Options

A. conjoint, collateral and open
B. conjoint, collateral and closed
C. collateral and open
D. collateral and closed

Answer

### Step-by-Step Solution:

1. **Understanding Vascular Bundles**: Vascular bundles are crucial structures in plants that facilitate the transport of materials such as water, minerals, and food. They consist of two main types of vascular tissues: xylem and phloem.

2. **Function of Xylem and Phloem**:
- **Xylem**: Responsible for transporting water and minerals from the roots to other parts of the plant.
- **Phloem**: Responsible for transporting food (sugars) produced in the leaves to other parts of the plant.

3. **Types of Vascular Bundles**: Vascular bundles can be classified based on the arrangement of xylem and phloem. The main types include:
- **Conjoined Collateral Open**: Phloem is located outside xylem, and there is a cambium layer between them.
- **Conjoined Collateral Closed**: Phloem is located outside xylem, but there is no cambium layer present.

4. **Analyzing the Dicot Leaf**: In dicot leaves, the vascular bundles are typically arranged in a specific manner.
- Since cambium is absent in the leaves, the option describing "conjoined collateral open" is incorrect because it requires the presence of cambium.

5. **Identifying the Correct Type**:
- The correct type of vascular bundle in a dicot leaf is **conjoined collateral closed**. In this arrangement, phloem is located on the outer side and xylem on the inner side, with no cambium present between them.

6. **Conclusion**: Therefore, the vascular bundles in a dicot leaf are classified as **conjoined collateral closed**.