photosynthesis is a kind of chemical process & if something is required by a living thing to perform a process then that living thing uses that something to perform that process ->  if something is required by a living thing to perform photosynthesis then that living thing uses that something to perform photosynthesis  if something is required by a living thing to perform photosynthesis then that living thing uses that something to perform photosynthesis & a plant requires sunlight for photosynthesis ->  a plant uses sunlight for photosynthesis  a plant uses sunlight for photosynthesis & photosynthesis makes food for the plant by converting carbon dioxide, water, and sunlight into carbohydrates ->  a plant uses sunlight for photosynthesis to make food  light is a kind of energy & sunlight is a kind of light ->  sunlight is a kind of energy  a plant uses sunlight for photosynthesis to make food & sunlight is a kind of energy -> sunight is a kind of energy that plants use to make food