The answer to your question is mass.
The respiratory system works directly with the circulatory system to provide oxygen to the body. Oxygen taken in from the respiratory system moves into blood vessels that then circulate oxygen-rich blood to tissues and cells.
The Ureters Move Urine from the Kidneys to the Bladder.
Animals take oxygen from the air and exhale carbon dioxide. Plants use this carbon dioxide and release oxygen into the air. ... Photosynthesis is important to living organisms because it is plants that ultimately serve as a foundation for the food web by providing a major source of food for other living organisms.
