Question

Describe one universal rule (e.g., gravity,diffusion, energy conversions, etc.) that you believe a human body obeys, explain how it accomplishes that feat, and describe how you know it to be true.

Answer 1

Diffusion - is the movement of molecules or atoms from a region of high concentration to a region of low concentration. In human body diffusion is seen in respiration, where the oxygen is inhaled and carbon dioxide is exhaled through gas exchange. After inhaling oxygen into the lungs, oxygen molecules diffuse from the alveolar air space of the lungs into the blood circulation. The concentration of oxygen in the deoxygenated blood is low, whereas the concentration of carbon dioxide is higher. Hence, the carbon dioxide molecules diffuse from the deoxygenated blood into the alveolar air space. The deoxygenated blood is converted into oxygenated blood when the oxygen that entered the blood, binds to the hemoglobin of RBC.

It is true because, when the concentration of carbon dioxide becomes higher inside the cells, it will lead to cell death, hence carbon dioxide is diffused into the lungs which has lower concentration of carbon dioxide and oxygen which is higher is taken in.