What do plant leaves contain?

Plant leaves contain chlorophyll, the green pigment responsible for photosynthesis, which allows plants to convert sunlight into energy. They also house various cells and structures, including stomata for gas exchange, and vascular tissues like xylem and phloem for transporting water, nutrients, and sugars. Additionally, leaves contain chloroplasts, where the photosynthesis process occurs, and can have various secondary metabolites that may serve protective or ecological functions.