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.
Confidence votes 9. The heart is a pump that both circulates blood and uses it to obtain oxygen and nourishment. Circulating blood enters the Atria (top chambers), is pumped to the Ventricles (bottom chambers) and out. Every time the heart contracts or beats, this happens.