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.
1. Cardiovascular circulation. Your heart is the power behind your cardiovascular circulatory system, pumping blood through your blood vessels, supplying every part of your body with the oxygen and nutrients it needs for proper functioning.