Which process forms carbohydrates from carbon dioxide, water, sunlight and chlorophyll?

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

Answer: (D)

Photosynthesis is the process by which green plants form carbohydrates from carbon dioxide and water using light energy captured by chlorophyll. In the chloroplasts, light drives reactions that combine CO2 from the air with water absorbed by roots to synthesize sugars such as glucose, while oxygen is released as a byproduct. Chlorophyll is essential because it absorbs light and powers these reactions. A simplified view of the reaction is: carbon dioxide plus water plus light energy yields glucose plus oxygen. This is the mechanism that builds carbohydrates from inorganic carbon and light energy, whereas respiration breaks down sugars for energy, transpiration is the loss of water from the plant, and germination is the sprouting of a seed using stored energy.