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 vitally important organ made of strong muscle tissue and is protected by the rib cage. It is about the size of your fist and sits slightly to the left of the middle of your chest. The heart is one of the only organs in the circulatory system but it is one of the most important organs in your entire body.This essential organ consists of four hollow chambers: two atria (plural form of atrium) on top and two ventricles below them.he heart is one of the only organs in the circulatory system but it is one of the most important organs in your entire body. This essential organ consists of four hollow chambers: two atria (plural form of atrium) on top and two ventricles below them.