All plant and animal groups existing together and the physical factors with which they interact compose an ecosystem<span>.</span>
D i believe, i could be wrong though
It radiates light and heat, or solar energy, which makes it possible for life to exist on Earth. Plants need sunlight to grow. Animals, including humans, need plants for food and the oxygen they produce. Without heat from the sun, Earth would freeze.
I believe the answer is linear :)
