The Structure of DNA

DNA stands for deoxyribonucleic acid, and it’s the chemical substance responsible for inherited characteristic in living organisms.
Each DNA molecule is made up of two long chains of small molecules called nucleotides. These long chains are arranged in a double helix configuration, much like a spiral ladder.
A nucleotide is composed of three smaller molecules: a sugar molecule (deoxyribose), a phosphate group, and a base.
There are four different kinds of bases in DNA: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).
The bases pair up in a specific way to form the rungs of the ladder: Adenine always pairs with Thymine, and Guanine always pairs with Cytosine. This is called complementary base pairing.
The order of the bases in DNA is referred to as the genetic code. This sequence is unique to each person and is instrumental in deciding their genetic traits.
Regions of DNA that carry genetic information are known as genes. Each gene determines different genetic characteristics.
The full set of genetic information in an organism is referred to as its genome.
DNA can replicate or copy itself before cell division, facilitating genetic inheritance. This process is highly accurate, though occasional mistakes lead to genetic mutations.
Damage to DNA can also lead to mutations, these changes can sometimes be beneficial, leading to evolution over generations.
In humans, almost every cell has a nucleus containing the same DNA, but different genes are ‘switched on’ in different types of cells making them specialised.