Why are ecosystems not considered “closed” systems?

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.

Aflame cell is at the end of each tubule of the nephridium malpighian tubules kidneys none of the above

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.