With increase in the total leaf area of a plant, there will be å corresponding increase in the

Options

A. number of metaxylem vessels
B. cross sectional area of phloem
C. xylem : phloem ratio
D. number of protoxylem vessels

Answer

**Step-by-Step Solution:**

1. **Understanding Leaf Area**: The total leaf area of a plant is determined by the length and breadth of the leaves. The area can be calculated by multiplying these two dimensions (Area = Length × Breadth).

2. **Impact of Increased Leaf Area**: As the total leaf area increases, several physiological and structural changes occur in the plant to accommodate the increased surface area for photosynthesis and transpiration.

3. **Metaxylem Vessels**: The number of metaxylem vessels does not change significantly with the increase in leaf area. These vessels are relatively constant and vary between monocots and dicots.

4. **Phloem Cross-Sectional Area**: The cross-sectional area of the phloem may not change directly with leaf area, as phloem primarily functions in transporting food produced by photosynthesis.

5. **Ratio of Phloem to Xylem**: As the leaf area increases, the demand for water and nutrients also increases, leading to a higher ratio of phloem to xylem. This is because more phloem is needed to transport the increased amount of photosynthates produced by the larger leaf area.

6. **Protoxylem Vessels**: Similar to metaxylem, the number of protoxylem vessels remains relatively constant and does not change with the increase in leaf area.

7. **Conclusion**: Therefore, with an increase in the total leaf area of a plant, there will be a corresponding increase in the ratio of phloem to xylem.

**Final Answer**: The correct option is the increase in the ratio of phloem to xylem.

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