DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs. In the human heart there is one atrium and one ventricle for each circulation, and with both a systemic and a pulmonary circulation there are four chambers in total: left atrium, left ventricle, right atrium and right ventricle.
The heart is a muscular organ that pumps blood to all the tissues in your body through a network of blood vessels. The right side of the heart pumps blood through the lungs where it picks up oxygen. The left side of the heart receives the blood containing oxygen and pumps the blood to the rest of your body. Your heart has four chambers and four valves that regulate blood flow: Left and right atria. Left and right ventricles.