During secondary growth of dicot stem, the growth of the phloem rays in relation to vascular cambium is

Options

A. Centripetal
B. Centrifugal
C. Acropetal
D. Concentric

Answer

**Step-by-Step Solution:**

1. **Understanding Secondary Growth in Dicot Stem:**
- Secondary growth in dicot stems occurs due to the activity of the vascular cambium, which is a lateral meristem. This process leads to an increase in the girth of the stem.

2. **Role of Vascular Cambium:**
- The vascular cambium is responsible for producing secondary xylem (wood) and secondary phloem. It divides to add new cells both inwardly (towards the center of the stem) and outwardly (towards the bark).

3. **Growth Direction of Xylem and Phloem:**
- The primary xylem is located at the center of the stem and grows inward as the vascular cambium produces secondary xylem.
- The primary phloem is located outside the primary xylem and grows outward as the vascular cambium produces secondary phloem.

4. **Identifying Growth Patterns:**
- The growth of the secondary xylem is termed **centripetal** because it moves towards the center.
- Conversely, the growth of the secondary phloem is termed **centrifugal** because it moves outward from the center.

5. **Conclusion:**
- Therefore, during the secondary growth of a dicot stem, the growth of the phloem rays in relation to the vascular cambium is **centrifugal**.

**Final Answer:**
- The growth of the phloem rays in relation to the vascular cambium during secondary growth of a dicot stem is **centrifugal**.

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