Answers

2016-07-16T16:34:02+08:00
We respire by breathing in the air,where oxygen is.and breathing it out with the waste product or the carbon dioxide.there are 4 phase of respiration. 1.BREATHING-it is the act of inhaling and exhaling air. 2.EXTERNAL RESPIRATION-Exchange of oxygen and carbon dioxide between the air and blood in our lungs. 3.INTERNAL RESPIRATION-the exchange of oxygen and carbon dioxide between the blood and the body cells. 4.CELLULAR RESPIRATION-The process of using oxygen to break down sugar in food,producing ATP in cells and releasing carbon dioxide as a waste product.
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