Photosynthesis powers roughly what share of Earth's ecosystems?

1. Almost every food chain starts with an organism that fixes carbon using light. 2. A wolf that eats a deer is at the end of a path that began with sunlight and photosynthesis. 3. Photosynthesis powers 99 percent of Earth's ecosystems. 4. Chemoautotroph-based ecosystems account for the small remainder. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 8 'Photosynthesis', sections 8.1-8.3_