Exarch and polyarch vascular bundles occur in
(a) Monocot stem
(b) Monocot root
(c) Dicot stem
(d) Dicot root

Options

A. Monocot stem
B. Monocot root
C. Dicot stem
D. Dicot root

Answer

To determine where exarch and polyarch vascular bundles occur, we can analyze the options provided:

1. **Understanding Vascular Bundles**:
- Vascular bundles are arrangements of xylem and phloem in plants.
- Exarch vascular bundles have the xylem located on the outside and phloem on the inside, while polyarch vascular bundles have multiple xylem and phloem strands.

2. **Evaluating the Options**:
- **(a) Monocot stem**: Typically has scattered vascular bundles, not specifically exarch or polyarch.
- **(b) Monocot root**: Monocot roots often exhibit a radial arrangement of vascular bundles and can have multiple xylem and phloem strands (polyarch). They also display exarch characteristics.
- **(c) Dicot stem**: Usually has vascular bundles arranged in a ring, not typically exarch or polyarch.
- **(d) Dicot root**: Dicot roots usually have a different arrangement and do not commonly exhibit exarch or polyarch characteristics.

3. **Conclusion**:
- Based on the analysis, exarch and polyarch vascular bundles are primarily found in the monocot root.

Therefore, the correct answer is **(b) Monocot root**.

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