Vascular bundles are conjoint, collateral, endarch and lack cambium between xylem and pholem in all, but not in

Options

A. Maize
B. Barley
C. Wheat
D. Sunflower

Answer

To solve the question regarding vascular bundles, we need to analyze the characteristics of the vascular bundles in the given plants: maize, barley, wheat, and sunflower.

### Step-by-Step Solution:

1. **Understanding Vascular Bundles**:
- Vascular bundles are structures that contain xylem and phloem, which are responsible for the transport of water, nutrients, and food in plants.
- The terms "conjoint," "collateral," "endarch," and "lack cambium" describe specific arrangements and characteristics of these bundles.

2. **Definitions**:
- **Conjoint**: Xylem and phloem are located in the same vascular bundle.
- **Collateral**: Phloem is located on the outside (periphery) and xylem on the inside.
- **Endarch**: The arrangement where the protoxylem is located towards the center and metaxylem is towards the periphery.
- **Lack Cambium**: There is no cambium layer between xylem and phloem.

3. **Analyzing the Options**:
- **Maize, Barley, and Wheat**: These are all monocots. In monocots, vascular bundles are typically:
- Conjoint
- Collateral
- Endarch
- Lack cambium between xylem and phloem
- **Sunflower**: This is a dicot. In dicots, vascular bundles are typically:
- Arranged in a ring formation
- May have cambium present between xylem and phloem.

4. **Conclusion**:
- The question states that vascular bundles are conjoint, collateral, endarch, and lack cambium in all but one of the given options. Since sunflower is a dicot, it does not conform to the same vascular bundle characteristics as the monocots (maize, barley, wheat).
- Therefore, the correct answer is **sunflower (option D)**, as it does not have the same vascular bundle arrangement as the others.

### Final Answer:
**Sunflower (option D)**

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