Conjoint, bicollateral and open vascular bundles are found

Options

A. roots
B. maize stem
C. mango stem
D. Cucurbita stem

Explanation

To answer the question regarding where conjoined, bicollateral, and open vascular bundles are found, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Vascular Bundles**:
- Vascular bundles are arrangements of xylem and phloem in plants. They can be classified based on their arrangement and presence of cambium.

2. **Types of Vascular Bundles**:
- **Conjoint Vascular Bundles**: Xylem and phloem are located together in the same bundle.
- **Bicollateral Vascular Bundles**: There are two layers of phloem on either side of the xylem, separated by cambium.
- **Open Vascular Bundles**: Presence of cambium allows for secondary growth, meaning the plant can grow in thickness.

3. **Identifying Incorrect Options**:
- **Roots**: Roots typically have radial vascular bundles, where xylem and phloem are located separately. Thus, they do not fit the criteria.
- **Maize (Monocots)**: Maize stems generally have closed vascular bundles, which means they lack cambium and do not exhibit bicollateral or open structures.

4. **Correct Example**:
- **Cucurbita (Pumpkin)**: The stem of Cucurbita from the Cucurbitaceae family exhibits bicollateral vascular bundles. It has two layers of phloem and one layer of xylem with cambium present, making it an example of a conjoint, bicollateral, and open vascular bundle.

5. **Conclusion**:
- The correct answer to the question is that conjoined, bicollateral, and open vascular bundles are found in the stem of Cucurbita.

### Final Answer:
Conjoint, bicollateral, and open vascular bundles are found in the stem of Cucurbita.