Which process uses light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates?

• A. Autotrophs
• B. Primary Production
• C. Cellular Respiration
• D. Photosynthesis

Answer: (D)

Photosynthesis uses light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates. In plants, algae, and some bacteria, chlorophyll captures sunlight and powers two main stages. First, the light-dependent reactions split water, releasing oxygen and generating energy carriers (ATP and NADPH). Then the Calvin cycle uses those carriers to fix carbon dioxide into sugars, building high-energy carbohydrates like glucose. This process forms the base of primary production, supplying organic matter and oxygen for other organisms. Autotrophs are organisms that produce their own food, often via photosynthesis (though some autotrophs use other energy sources). Primary production is the rate at which these organisms create biomass from inorganic carbon, while cellular respiration is the process that releases energy by breaking down sugars, using oxygen and producing carbon dioxide. The description given points to photosynthesis.