The hearts job is to pump blood around your body to keep you alive. There is double circulation because the oxygenated blood comes from the lungs and out the aorta into the body as well as the deoxygenated blood comesfrom around the body and circulates out the pulmomary artery into the lungs
Blood is the fuel that keeps you going! Oxygenated blood is brought to organs and tissues via the arteries, while veins bring deoxygenated blood back to the heart to be replenished. The point is, without the respiratory system your blood would be useless.
The circulatory and respiratory systems work together to circulate blood and oxygen throughout the body. Air moves in and out of the lungs through the trachea, bronchi, and bronchioles. Blood moves in and out of the lungs through the pulmonary arteries and veins that connect to the heart.
Answer:
A Flowers started to be pollinated by trees.
Explanation:
Hopefully this helps
This would be called a Parasitic Relationship.