Please provide a detailed explanation of the process of photosynthesis, including its importance in the ecosystem. Your response should contain at least 500 words, at least 10 sentences, and include keywords such as *carbon dioxide*, *water*, *chlorophyll*, *sugar*, *oxygen*, *sunlight*, *energy*, *plants*, *photosynthesis*, and *ecosystem*. Highlight at least 3 sections in your answer with markdown, i.e. *highlighted section*.
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