There are different amounts of Oxygen and Carbon Dioxide in the air when we inhale and exhale caused by the body’s systems that naturally extract oxygen from inhaled air to provide for the human body. All living things are either single-celled or multicellular. (Scientific Principle 2) According to Scientific Principle 3, Multicellular organisms, such as the human body, are organized into systems that perform different functions. The respiratory system performs a function of inhaling and exhaling air to benefit the body. When we inhale, we breathe in air which contains Carbon dioxide, Oxygen, Argon, Nitrogen, and other gases. The air travels through your nose or mouth and goes through the pharynx. The air then goes down the trachea and into the bronchial tubes. The air then gets passed into the alveoli into the …show more content…
The amount of Oxygen in the exhaled air is less than the amount of Oxygen in the inhaled air. This is can be proven through lab testing. In Activity 6.1, we used a candle to determine the amount of Oxygen in inhaled and exhaled air. This is because fire needs three things to be present: fuel, heat source, and oxygen. According to Scientific Principle 5, fire needs Oxygen to burn. Therefore, the more Oxygen in the air, the longer the candle will burn. Under a beaker with inhaled air, the candle burned 2.3 seconds longer than under a beaker with exhaled air. This proves that there is more Oxygen in inhaled air than exhaled air. Also, there is more Carbon dioxide in exhaled air than in inhaled air. That can be proven by a lab performed. In Activity 6.1, we performed a breathing test with bromothymol blue solution, an indicator for Carbon dioxide. (BTB) In room air, or inhaled air, the bromothymol blue was a dark green color. However, when under exhaled air, the BTB solution turned a bright yellow, indicating a drastic increase in the amount of Carbon dioxide in the