Answer:
1- the sun
2-Plants performing photosynthesis convert carbon dioxide to organic carbon compounds using sunlight as a source of energy; these compounds go on to fuel nearly all other organisms in the ecosystem, from bacteria to animals.
3-The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat.
Step-by-step explanation:
1-Energy is all around us and comes from many sources. One of the most important sources of energy is the sun. The energy of the sun is the original source of most of the energy found on earth. We get solar heat energy from the sun, and sunlight can also be used to produce electricity from solar (photovoltaic) cells.
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