Question

living things depend upon each other for food. every living thing is a link in a food chain. a food chain shows the order in which living things feed upon other living things.
look at figure a. it shows a food chain. the arrows in the food chain show the direction that food moves along the chain.
not all organisms eat the same kinds of food. therefore, there are many different food chains. but, all food chains begin with producers.
why?
producers are the only organisms that can make their own food, using energy from the sun.
why is the sun the source of energy in an ecosystem?__________________________
__________________________
__________________________

Explanation:

Producers, like plants (grass in the example), use sunlight for photosynthesis to make food. Consumers (rabbit, snake, hawk) get energy by eating other organisms. Since producers rely on the sun for energy - making food, and all other organisms in the food chain depend on producers (directly or indirectly), the sun is the ultimate energy source.

Answer:

Producers use sunlight to make food. Consumers depend on producers (directly or indirectly). So, the sun is the source of energy as it powers the food - making process in producers, which then support all other organisms in the ecosystem.