In an energy pyramid, the producers or the autotrophs will form the base. The autotrophs are those which are able to prepare their own food. The autotrophs include the green plants and algae which contain a specialized organelle called as chloroplast. The chloroplast perform the process of photosynthesis to prepare food. The leaves are considered as the photosynthetic parts of a plant.
The organisms which do not contain chloroplast and depend on others for nutrition are called heterotrophs.