Vascular tissue of monocot root is

Options

A. collateral, open diarch and endarch
B. radial, open tetrach an exarch
C. radial, open and endarch
D. radial, closed and exarch

Answer

### Step-by-Step Solution:

1. **Understanding Vascular Tissue**: The vascular tissue in plants consists of xylem and phloem, which are responsible for the transport of water, nutrients, and food.

2. **Identifying Monocot Roots**: Monocot roots have a specific arrangement of vascular tissues that differ from dicot roots. It is essential to understand the characteristics of monocot roots to answer the question correctly.

3. **Exarch Arrangement**: In monocot roots, the arrangement of xylem is exarch. This means that the protoxylem (the first formed xylem) is located towards the outer side of the root, away from the pith. This is a common feature in both monocot and dicot roots.

4. **Distinguishing Between Endarch and Exarch**: Since we are discussing monocot roots, we can eliminate the endarch arrangement (where protoxylem is towards the center) as it does not apply to roots.

5. **Conjoint vs. Radial Bundles**:
- **Conjoint Bundles**: These have xylem and phloem on the same radius and are typically found in stems (both monocot and dicot).
- **Radial Bundles**: In this arrangement, xylem and phloem are located on separate radii. This type of arrangement is characteristic of roots, including monocot roots.

6. **Closed vs. Open Bundles**:
- **Open Bundles**: These contain vascular cambium, allowing for secondary growth, which is common in dicots.
- **Closed Bundles**: In monocots, the vascular cambium is absent, meaning there is no secondary growth. Therefore, the vascular bundles in monocot roots are considered closed.

7. **Conclusion**: Based on the above points, the vascular tissue of monocot roots is characterized by:
- An **exarch arrangement** (protoxylem towards the outer side).
- A **radial arrangement** (xylem and phloem on separate radii).
- **Closed bundles** (absence of vascular cambium).

Thus, the correct answer is that the vascular tissue of monocot roots is **radial and closed**.