2. key concept compare
standing-water ecosystems to
flowing-water ecosystems. how
are they alike? how are they
different?

Food provides molecules that serve as fuel and building material for all organisms. plants undergo photosynthesis and make their own food. other organisms, like us and the horse seen above, are consumers and eat food. how do all organisms use food as fuel? be sure to include the name of the process in your answer. me.

20 the main source of energy for our planet comes from the

What happens when a scientific theory is shown to be an accurate description of a phenomenon?