If protoxylem lies towards the centre (pith) and the metaxylem lies towards the periphery of the organ, then this type of primary xylem is called :-

Options

A. Exarch
B. Endarch
C. Mesarch
D. Polyarch

Answer

To determine the type of primary xylem where protoxylem lies towards the center (pith) and metaxylem lies towards the periphery of the organ, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Xylem Structure**:
- Xylem is a complex permanent tissue responsible for the conduction of water and minerals in plants. It consists of different types of cells, including protoxylem and metaxylem.

2. **Identifying Protoxylem and Metaxylem**:
- Protoxylem is the first-formed xylem that develops during the early stages of plant growth, while metaxylem forms later and is usually larger in diameter.

3. **Analyzing the Position of Protoxylem and Metaxylem**:
- In the given scenario, protoxylem is located towards the center (pith) of the organ, and metaxylem is located towards the periphery.

4. **Classifying the Type of Xylem**:
- There are two main arrangements of xylem based on the position of protoxylem and metaxylem:
- **Endarch**: In this arrangement, protoxylem is located towards the center, and metaxylem is towards the periphery.
- **Exarch**: In this arrangement, protoxylem is located towards the periphery, and metaxylem is towards the center.

5. **Conclusion**:
- Since the question specifies that protoxylem is towards the center and metaxylem is towards the periphery, this arrangement corresponds to the endarch condition.

### Final Answer:
The type of primary xylem where protoxylem lies towards the center and metaxylem lies towards the periphery is called **Endarch**.

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