Question

Ringing/girdling experiments demonstrate

• A. Phloem is responsible for translocation of food
• B. Xylem is responsible for ascent of sap
• C. Transpiration pull
• D. Both (a) and (b).

Answer 1

The correct option is D Both (a) and (b).

Girdling experiment is used to identify the tissue through which the food is transported. In this experiment, a ring of bark (phloem) is removed from the wood by a technique known as girdling. Since the woody xylem part present on inner side remains intact, water and nutrient reach the leaves. After the preparation of the photosynthate, it is not transported to other parts below the girdle since the phloem part is removed. So it is observed that there is an accumulation of the food/sugar just above the girdle region. This experiment shows that the phloem tissue aids food transport. While no effect on water transport shows that xylem is responsible for the ascent of sap.

So, the correct option is 'Both (a) and (b)'.