1.Heart will only pumps blood to entire body. Bone marrow will produce red blood cells for our body.
2.Not enough iron and protein to produce blood.
3.White blood cell help to defend our body from infectious disease and invaders.
4.Pulmonary vein and pulmonary artery are both connected to the lungs.Pulmonary artery transport deoxygenated blood from heart to lungs to refill oxygen back to the blood and at the same time, it will remove carbon dioxide that produced by our body cell then the oxygenated blood will carry back to lungs by pulmonary vein. Aorta use to transport oxygen from heart to the entire body cells and vena cava helps to transport deoxygenated blood from body cells back to the heart.
5.Blood will carry both oxygen and carbon dioxide.