In a ring girdled plant :

Options

A. the root dies first
B. the shoot and root die together
C. neither root nor shoot will die
D. the shoot dies first

Explanation

**Step-by-Step Solution:**

1. **Understanding Ring Girdling**: Ring girdling involves the removal of a ring of bark and phloem from a plant stem. This process disrupts the vascular system, particularly the phloem, which is responsible for transporting nutrients and sugars produced in the leaves to the rest of the plant.

2. **Function of Phloem**: The phloem is a type of vascular tissue that transports organic nutrients, particularly sucrose, from the leaves (where they are produced during photosynthesis) to other parts of the plant, including the roots.

3. **Impact of Girdling on Nutrient Transport**: When the phloem is removed due to girdling, the flow of nutrients from the leaves to the roots is halted. As a result, the roots do not receive the necessary nutrients and sugars they need to survive.

4. **Consequences for the Roots**: Without the supply of nutrients from the phloem, the root cells begin to starve. Over time, this lack of nutrients leads to the death of root tissues.

5. **Timing of Death**: Since the roots are deprived of essential nutrients first, they will begin to die before the shoot. The shoot may survive for a while due to stored nutrients, but eventually, it will also die if the roots are not functioning.

6. **Conclusion**: Therefore, in a ring girdled plant, the roots die first due to the lack of nutrient supply from the phloem.

**Final Answer**: The root dies first.

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