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.
An organ is a specialized grouâ¦p of tissues that performs a particular function, and often more than one function. Examples of organs are the brain, heart, eyes, bones, intestines, pancreas, rectum, lymph nodes, ears, stomach, liver, and gallbladder. We have close to seventy-eight organs in our body. Organs may work together to form a body system.