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 coronary circuit is the shortest circulation in the body. Blood in the chambers of the heart provide little oxygen & nutrients to the heart wall. The myocardium is too thick for effective diffusion. Therefore, the heart has its own circulation. In fact, the first branches of the aorta go back to the heart itself. These are the right & left coronary arteries.