Question

Under conditions of bright light, which part of the transpiring plant will have the lowest water potential?

• A. Xylem vessels in the leaves
• B. Xylem vessels in the roots
• C. Root hairs
• D. Spongy mesophyll of the leaves

Answer 1

The correct option is D Spongy mesophyll of the leaves

Water moves from a region of higher water potential to a region of lower water potential.

As plants absorb water using their roots from the soil, the root hairs and the xylem vessels in the roots will have the highest water potential. Since the leaves play a major role in the process of transpiration, the water travels upwards through the xylem vessels of the roots to the xylem vessels of the leaves. Water, then finally reaches the spongy mesophyll cells of the leaves. Hence, the spongy mesophyll cells of the leaves will have the lowest water potential.