Final answer:
At O2 concentrations of 10-12, the body responds by increasing the synthesis of carrier molecules like hemoglobin to transport oxygen from the lungs to the tissues where it is used to provide energy.
Step-by-step explanation:
At O₂ concentrations of 10-12, the body would likely respond by increasing the synthesis of highly soluble carrier molecules, such as hemoglobin, to bind and transport O₂.
These carrier molecules facilitate the transport of O₂ from the lungs to the tissues, where it is used to provide energy through the oxidation of food molecules. This allows for a higher total dissolved O₂ concentration in the body, which is essential for supporting the energy needs of multicellular organisms, including humans.