DNA replication is the process by which DNA makes a copy of itself during cell division. 1  The first step in DNA replication is to âunzipâ the double helix structure of the DNA molecule.
The heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, and also assists in the removal of metabolic wastes. The heart is located in the middle compartment of the mediastinum in the chest.
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.