What is the role of transfer cells in sugar translocation?

Options

A. They serve to load photosynthate into sieve tubes
B. They increase DPD of sieve tubes
C. They synthesise P-proteins
D. They synthesise callose

Answer

**Step-by-Step Solution:**

1. **Understanding Transfer Cells:**
- Transfer cells are specialized plant cells that play a crucial role in the movement of substances within the plant, particularly in sugar translocation.

2. **Structure of Transfer Cells:**
- These cells have an increased cell wall growth which enhances the surface area of the plasma membrane. This structural adaptation is essential for efficient transport.

3. **Energy Supply:**
- Transfer cells are rich in mitochondria, which are the powerhouses of the cell. The abundant mitochondria provide the necessary energy (in the form of ATP) to facilitate active transport processes.

4. **Source of Sugars:**
- Sugars, referred to as photosynthates, are produced during photosynthesis, primarily in the leaves of the plant.

5. **Active Transport Mechanism:**
- The photosynthates generated in the leaves need to be transported to other parts of the plant. This transport occurs through active transport mechanisms from the source cells (leaves) to the sieve tubes.

6. **Function of Transfer Cells:**
- The primary role of transfer cells is to load these photosynthates into the sieve tubes. This loading is essential for the distribution of sugars throughout the plant.

7. **Conclusion:**
- Therefore, the role of transfer cells in sugar translocation is to serve as a mechanism to load photosynthates into the sieve tubes, ensuring that the sugars produced during photosynthesis are effectively transported to all parts of the plant.

**Final Answer:**
Transfer cells serve to load photosynthate into sieve tubes, facilitating sugar translocation within the plant.

---