Answer:
Gas exchange during respiration occurs primarily through diffusion. Gas molecules move from a region of high concentration to a region of low concentration. Blood that is low in oxygen concentration and high in carbon dioxide concentration undergoes gas exchange with air in the lungs.
Explanation:
Not the same and they is not in a relationship
Answer:
This should help you understand more about DNA replication
and it also has a picture.
C. They are specialized tissues that form an organ system.
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