Which statement about transpiration is correct?

• A. It is the process of sugar transport in phloem.
• B. It is the loss of water from the plant through stomata.
• C. It is the uptake of water by roots.
• D. It is the breakdown of chlorophyll.

Answer: (B)

Transpiration is the loss of water vapor from the plant, primarily through the stomata on the leaves. When stomata open for carbon dioxide to enter for photosynthesis, water vapor escapes, driving the upward flow of water from the roots through the xylem by cohesion and tension. This water movement helps pull nutrients up from the roots and also cools the plant. So, the statement that transpiration is water loss through stomata is correct. The other ideas describe different processes: transporting sugars in the phloem is translocation, not transpiration; water uptake by roots is the absorption phase before transpiration, not the loss part; and breakdown of chlorophyll relates to senescence or pigment degradation, not transpiration.