All animals, from humans to the dinosaurs are part of the carbon cycle. When animals eat food, they get carbon in the form of carbohydrates and proteins. In animals, oxygen combines with food in the cells to produce energy for daily activity and then gives off carbon.
Through the process of respiration , in lung the carbon dioxide from the blood is exchanged with oxygen.
The smallest dunctional unit if the lung is the alveoli
At this level the gases are exchange through the capillaries present close to the alveoli.
The concentration gradient ,meaning the greater amount of oxygen present in the lungs and greater amount of carbon dioxide in the blood creates a gradient that allow the movment of oxygen into the blood and carbon dioxide in the alveoli through the membrane .
Partial pressure created allows the easy movement .The carbon dioxide get into the trachea and expelled through nose and mouth.
This is referred to as co-evolution. It involves the reciprocal evolution of 2 species. This kind of evolution can be seen in mutualism (like the choices described above), and also predator-prey, host-parasite relationships. The term co-evolution was coined by Paul R. Ehrlich and Peter H. Raven in 1964.
