Green plants cannot live without light because it is necessary for which process?

• A. Manufacture of food
• B. Transpiration
• C. Respiration
• D. Nutrient uptake

Answer: (A)

Light is required for photosynthesis, the process plants use to manufacture their food. In photosynthesis, chlorophyll captures light energy to drive reactions that convert carbon dioxide and water into glucose, the sugar that serves as the plant’s food, while releasing oxygen. Without light, this food-making process cannot occur, so the plant cannot synthesize the energy and building blocks it needs to grow and survive. Transpiration, respiration, and nutrient uptake happen independently of light to varying degrees, but they do not provide the essential energy source plants rely on to produce their own nourishment.