What is the process by which plants convert sunlight into food?

Photosynthesis is the process through which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. This process primarily occurs in the chloroplasts of plant cells, which contain chlorophyll—the green pigment that captures light energy. Through a series of complex chemical reactions, light energy is transformed into chemical energy stored in the form of glucose, which serves as food for the plant. This process is not only vital for the survival of the plant itself, as it provides the necessary energy for growth and development, but it also plays a crucial role in the Earth's ecosystem. By producing oxygen as a byproduct, photosynthesis contributes to the breathable atmosphere that supports life on the planet.

The other processes mentioned—respiration, transpiration, and assimilation—serve different functions in plant biology. Respiration involves breaking down glucose for energy, transpiration is the process of water movement through a plant and its evaporation from aerial parts, and assimilation refers to the incorporation of nutrients into the plant's cells. Each of these processes is important, but none involves the conversion of sunlight into food as photosynthesis does.