When protoxylem faces pericycle , it is called-

Options

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

Answer

To solve the question "When protoxylem faces pericycle, it is called-", we need to understand the arrangement of xylem in relation to other tissues in the plant. Here’s a step-by-step explanation:

### Step 1: Understand the Terms
- **Protoxylem**: This is the first-formed xylem in a plant, responsible for the conduction of water and minerals.
- **Pericycle**: This is a layer of cells located just inside the endodermis in roots, from which lateral roots arise.

### Step 2: Identify the Arrangements of Xylem
Xylem can be arranged in different ways:
- **Endarch**: Protoxylem is located towards the center, and metaxylem is towards the periphery.
- **Exarch**: Protoxylem is located towards the periphery, and metaxylem is towards the center.
- **Mesarch**: Both protoxylem and metaxylem are located in the middle.
- **Polyarch**: Refers to multiple protoxylem strands.

### Step 3: Analyze the Question
The question asks specifically about the condition when protoxylem faces the pericycle. This means we need to identify which arrangement corresponds to this scenario.

### Step 4: Determine the Correct Answer
When protoxylem is facing the pericycle, it is indicative of an **exarch** arrangement. In this arrangement, the protoxylem is positioned towards the outer side (periphery) while the metaxylem is located towards the center.

### Conclusion
Thus, the correct answer to the question is **Option C: Exarch**.

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