Test center: Nature and significance of photosynthesis Special topic: analysis: autotrophic: refers to the metabolic type in which most green plants and a few bacteria use light energy or chemical energy as energy and carbon dioxide in the environment as carbon source to synthesize organic matter and store energy. Heterotrophic: Inorganic substances cannot directly synthesize organic substances. Ready-made organic matter must be ingested to maintain a nutritious lifestyle. Autotrophic organisms: green plants, photosynthetic bacteria, chemosynthetic bacteria. Heterotrophs: Animals, people, most bacteria and fungi. The difference between autotrophs and heterotrophs is that autotrophs can use inorganic substances to synthesize their own organic substances, while heterotrophs can only use organic substances and cannot synthesize their own organic substances from inorganic substances. So choose: D. Comments:.