Which of the following arrangements of xylem is found in the stem of plants ?

Options

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

Answer

To solve the question regarding the arrangement of xylem found in the stem of plants, let's analyze the options provided systematically.

### Step 1: Understand the Types of Xylem Arrangements
- **Endarch**: In this arrangement, the protoxylem (the first formed xylem) is located towards the center of the stem, while the metaxylem (the later formed xylem) is towards the periphery. This arrangement is typical in the stems of flowering plants.

- **Exarch**: This is the opposite of endarch. Here, the protoxylem is directed towards the periphery, and the metaxylem is towards the center. This arrangement is characteristic of roots, not stems.

- **Mesarch**: This arrangement is characterized by having more than one strand of primary xylem, where the xylem develops from the middle of the strand in both directions. This is seen in some ferns but is not the primary arrangement in most flowering plant stems.

- **Polyarch**: This arrangement is typically found in monocot roots, where multiple strands of xylem are present.

### Step 2: Identify the Correct Arrangement for Stems
From the definitions:
- Endarch is the arrangement found in the stems of flowering plants.
- Exarch, mesarch, and polyarch are either found in roots or specific types of plants that do not represent the general case for stems.

### Conclusion
The correct answer to the question is **Endarch**, as it is the arrangement of xylem found in the stem of flowering plants.

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