AP Biology 2008-2009 gills alveoli elephant seals Gas Exchange Respiratory Systems.
AP Biology Why do we need a respiratory system? O2O2 food ATP CO 2 Need O 2 in for aerobic cellular respiration make ATP Need CO 2 out waste.
Gas Exchange Respiratory Systems (Ch. 42) Why do we need a respiratory system? O2O2 food ATP CO 2 respiration for respiration Need O 2 in – for aerobic.
