Which process removes carbon dioxide from the atmosphere and stores carbon in biomass?

• A. Photosynthesis
• B. Combustion
• C. Decomposition
• D. Respiration

Answer: (A)

Photosynthesis is the process by which plants, algae, and some bacteria use light energy to drive a reaction that takes in carbon dioxide and water and yields glucose and oxygen. As plants build organic molecules to grow, they remove carbon dioxide from the air and store that carbon in their biomass—roots, stems, and leaves. This is how carbon becomes part of living matter and is held in plant tissues for as long as the plant remains. Other options don’t fit this effect: combustion releases carbon dioxide when stored carbon is burned; decomposition and respiration release carbon dioxide back into the air as organisms break down organic matter for energy. So photosynthesis uniquely removes CO2 from the atmosphere and stores carbon in biomass.