When stem of plant is girdled (ringed) :

Options

A. The root dies first
B. The shoot dies first
C. The roots and the shoot will die at the same time
D. neither the root nor the shoot wilts

Answer

**Step-by-Step Solution:**

1. **Understanding Girdling (Ring Barking):**
- Girdling, also known as ring barking, is a process where a ring of bark is removed from the stem of a plant. This removal disrupts the flow of nutrients and water within the plant.

2. **Impact on Phloem:**
- The phloem is the tissue responsible for transporting sugars and other organic nutrients from the leaves to other parts of the plant, especially the roots. When the phloem is damaged or removed through girdling, this transport process is halted.

3. **Consequences of Phloem Removal:**
- Without the ability to transport sugars (primarily sucrose) to the roots, the roots begin to starve. This lack of nutrients means that the roots cannot sustain themselves or take up additional minerals and water from the soil.

4. **Root Death:**
- As the roots are deprived of essential nutrients, they will eventually die. This is the first major consequence of girdling.

5. **Impact on the Whole Plant:**
- Once the roots die, the plant cannot absorb water and minerals, leading to further deterioration. The shoot system (stems and leaves) will also begin to die due to the lack of nutrients and water, but this occurs after the roots have already died.

6. **Conclusion:**
- Therefore, when a plant is girdled, the roots die first due to the inability to receive the necessary nutrients, which ultimately leads to the death of the entire plant.

**Final Answer:**
When the stem of a plant is girdled, the roots die first due to the disruption of phloem transport, leading to the eventual death of the entire plant.

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