AThe shoot dies first
BThe root dies first
CNeither shoot nor root dies
DThe root and shoot die together
Answer:
B. The root dies first
Read Explanation:
Phloem is a vascular tissue of the plants and mainly transports the nutrients (food or energy sources) from food stores of the plants to its different parts (or organs) including roots, stems, and reproductive tissues.
Therefore, the transport of various materials in phloem is usually bidirectional including towards the upper parts as well as lower parts of the plants.
This helps ensure the supply of nutrients from photosynthetic sites (leaves) to other plant parts where photosynthesis does not occur normally.
On ring girdling, the bark and phloem part of the stem is being removed.
As a result, the movement of nutrients and other minerals from shoot part to root part of the plant does not occur.
Hence, the root cells and tissues starve due to prolonged unavailability of food for their survival.
This would further lead to death of cells and tissues of roots after some period of time.
Therefore, the root dies first in a ring girdled plant.