What process must happen to gaseous nitrogen before plants can use it to grow?

The job of the heart is to pump blood to the lungs and to the body. There are two circuits, the pulmonary circuit and the systemic circuit. The pulmonary circuit is where the arteries carry deoxygenated blood and veins carry oxygenated blood which is different than the rest of the arteries and veins in the body.

The pulmonary circuit is where blood is pumped from the right ventricle of the heart through the pulmonary artery which carries deoxygenated blood and takes it to the lungs.

In the systemic circuit, the left ventricle pumps blood to the aorta (largest artery) which is then caries oxygenated blood away from heart to the body. And the blood must be rich in oxygen to get to be pumped to the whole body.