Which term describes water loss from a plant through the stomata?

• A. Translocation
• B. Photosynthesis
• C. Transpiration
• D. Respiration

Answer: (C)

Transpiration is the process by which water leaves a plant, primarily through the stomata, which are tiny openings on the leaf surface controlled by guard cells. When stomata open to admit carbon dioxide for photosynthesis, water vapor inside the leaf also diffuses out into the drier air, creating a vapor-pressure gradient that drives water loss. This evaporation helps pull water up from the roots through the xylem, aiding nutrient transport and helping cool the leaf. Photosynthesis, in contrast, is about using light energy and CO2 to make sugars, not about water loss. Respiration is the metabolic breakdown of sugars to release energy, and translocation refers to moving sugars through the phloem.