Organ systems are made up of tissues which are made up of cells.
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Answer:
So where then did all the carbon that living organisms are built of come from? It turns out that most of the carbon we use today came from a collision with another smallish planet about 4.4 billion years ago.
Chewing bread, tearing paper, breaking rocks
Answer:
Most of the earliest microorganisms were prokaryotes so it would make sense for them to go through photosynthesis to create glucose for energy. They also could have gotten energy from salt water.
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