green plants are a kind of producer & a producer is a source of sugar in an ecosystem ->  plants are a source of sugar in an ecosystem  plants are a source of sugar in an ecosystem & a source of something produces that something ->  plants produce sugar in an ecosystem  photosynthesis makes food for the plant by converting carbon dioxide, water, and sunlight into carbohydrates & sugar is a kind of food ->  photosynthesis makes sugar for plants  plants produce sugar in an ecosystem & photosynthesis makes sugar for plants -> plants produce sugar during photosynthesis