Once the DNA in a cell is replicated, the cell can divide into two cells, each of which has an identical copy of the original DNA. DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
The heart is a vital organ located in the center of the chest with a slight tilt to the left. Using rhythmic muscle contractions, it circulates blood through veins and arteries, which supplies tissues with oxygenated blood and disposes waste.
The heart is a hollow, cone-shaped muscle located between the lungs and behind the sternum (breastbone). Two-thirds of the heart is located to the left of the midline of the body and 1/3 is to the right (see Figure 1). The apex (pointed end) points down and to the left. It is 5 inches (12 cm) long, 3.5 inches (8-9 cm) wide and 2.5 inches (6 cm) from front to back, and is roughly the size of your fist.