How do autotrophs differ from heterotrophs and how does it relate to the trophic pyramid?

Photosynthetic and chemosynthetic organisms can be called either primary producers or autotrophs because they make their own food. The bodies of autotrophs are rich sources of chemical energy for any organisms capable of consuming them. Heterotrophs are organisms such as animals that must consume food from other organisms because they are unable to synthesize their own food molecules. Some heterotrophs consume autotrophs, and some consume other heterotrophs. The primary producers are mostly chlorophyll-containing photosynthesizers. The animal heterotrophs that eat them are called primary consumers (or herbivores), the animals that eat them are called secondary consumers (or carnivores), and so on to the top consumer (or top carnivore).

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