In a transverse section of a sunflower root :

Options

A. Both protxylem and metaxylem vessels are present towards the periphery .
B. Both protxylem and metaxylem vessels are present towards the centre.
C. The protoxylem vessels are present towards the centre and metaxylem vessels are present towards the periphery.
D. The protoxylem vessels are present towards the periphery and metaxylem vessels are present towards the centre .

Answer

**Step-by-step Solution:**

1. **Understanding the Structure of the Sunflower Root**: In a transverse section of a sunflower root, we need to identify the arrangement of xylem tissues. The xylem is responsible for the transport of water and nutrients.

2. **Identifying Xylem Types**: The xylem is divided into two types: protoxylem and metaxylem. Protoxylem is the first xylem to develop and is typically located closer to the outer edge of the root, while metaxylem develops later and is found more centrally.

3. **Analyzing the Arrangement**: In the sunflower root, the arrangement of xylem is such that the protoxylem is located towards the periphery (outer side) and the metaxylem is located towards the center. This specific arrangement is referred to as an "exarch condition."

4. **Evaluating the Options**:
- Option A: Both protoxylem and metaxylem vessels are present towards the periphery. (Incorrect)
- Option B: Both protoxylem and metaxylem are present towards the center. (Incorrect)
- Option C: The protoxylem vessels are present towards the center and metaxylems are towards the periphery. (Incorrect)
- Option D: The protoxylem vessels are present towards the periphery, and metaxylems are towards the center. (Correct)

5. **Conclusion**: The correct answer is that in the transverse section of a sunflower root, the protoxylem vessels are located towards the periphery, while the metaxylem vessels are located towards the center, confirming the exarch condition.