in physiology respiration is the movement of oxygen from the outside environment to the cells with tissues and the removal of carbon dioxide in the opposite direction .. in contrast exhalation is usually a passive process
The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation).This exchange of oxygen and carbon dioxide is called respiration.
**Physiological respiration and cellular respiration are not the same. People sometimes use the word "respiration" to refer to the process of cellular respiration, which is a cellular process in which carbohydrates are converted into energy. The two are related processes, but they are not the same.
Cellular respiration that proceeds in the absence of oxygen is anaerobic respiration. Cellular respiration that proceeds in the presence of oxygen is aerobic respiration. Anaerobic respiration evolved prior to aerobic respiration.
A fossil would from through mineral replacement by replacing the existing material of the animals bones with minerals, to become petrified. The Minerals will keep the fossil preserved longer.