In biology, the term homeostasis<span> refers to the ability of the body to maintain a stable internal environment despite changes in external conditions</span>
Lungs (20)Lose elasticity and capacity (40% between ages 20 and 80), increasing difficulty to oxygenate blood.
Carbon<span> is a key component of </span>all<span> known life on Earth. Complex molecules are </span>made up of carbon<span> bonded with other elements, especially oxygen, hydrogen and nitrogen.</span>Carbon<span> is abundant on Earth.</span>
