What Is DNA?
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule.
Deoxyribonucleic acid (DNA) is a nucleic acid present in the cells of all living organisms. It is often referred to as the “building blocks of life,” since DNA encodes the genetic material which determines what an organism will develop into. In addition to maintaining the genetic blueprints for its parent organism, DNA also performs a number of other functions which are critical to life. This nucleic acid was first identified in 1889, when researcher Friedrich Miescher found a substance he called “nuclein” in human cells. In the early 20th century, several researchers including Phoebus Levene and William Astbury performed additional research on nuclein, beginning to understand its components, structure, and role in life. A seminal article published in Nature in 1953 by James Watson and Franklin Crick is often cited as the breakthrough moment in DNA research, as it correctly posited the distinct structure of DNA, with significant help from scientist Rosalind Franklin.
Deoxyribonucleic acid (DNA) is a chemical substance found in most cells of the human body (and in most cells of all living organisms). The DNA in an individual’s blood is the same as the DNA found in their hair roots and skin cells. DNA stores information that is needed for passing down our genetic characteristics from one generation to the next – for example, what we look like and how we develop – hence it is also known as our genetic blueprint. Half of each person’s DNA comes from their mother and the other half from their father.
