gills

27 05, 2017

How do animals breathe? Respiration, Evolution, Biology

By |2018-04-21T11:56:44-07:00May 27th, 2017|Biology|Comments Off on How do animals breathe? Respiration, Evolution, Biology

Fish gills The first cells, which evolved about 3.8 billion years ago, needed carbon dioxide to live and not oxygen. They needed the carbon dioxide to help them break down [...]

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