What are the primary leaf functions?

• A. Photosynthesis and transpiration and respiration
• B. Photosynthesis
• C. Transpiration
• D. Respiration

Answer: (A)

Leaves perform several key roles that keep a tree alive and growing. The primary function is to carry out photosynthesis, using chlorophyll to capture light energy and fix carbon dioxide into sugars that feed growth and metabolism. At the same time, leaves regulate water and gas exchange through stomata, driving transpiration which helps pull nutrients from the roots and also cools the leaf. Leaves also carry out respiration, using stored sugars to generate the energy needed for cellular processes. Taken together, photosynthesis, transpiration, and respiration cover the main activities leaves perform. Relying on only one of these processes misses essential leaf functions, so listing all three provides the complete picture.