A: We’ve all heard of ‘DNA’, and we know that we have DNA in our body, but what really is DNA? As a basic scientific definition, DNA stands for deoxyribonucleic acid, and is the building block for a chromosome. Each chromosome is made up of a pair of DNA strands and is located in the nucleus of each cell in our body. Each strand of DNA is made up of smaller protein molecules, called nucleotides, more commonly known as base molecules, or bases for short. There are four (4) bases – adenine (A), cytosine (C), guanine (G), and thymine (T). The two strands of DNA are linked together at each base by hydrogen bonds. This pair of DNA strands twist around a central axis to give the special double helix shape with which we are all so familiar.

The DNA strands wrap around a group of eight histone protein molecules, creating a large ball-shaped structure, called a nucleosome. These nucleosomes arrange themselves into a helical shape, similar to a bungee telephone cord, in order to be as compact as possible. This helical strand is compacted even further by ‘supercoiling’ and overall forms a single rod-shaped structure called a chromatin.