What is DNA?
DNA (deoxyribonucleic acid) is the molecule that determines and controls biological functioning. The human DNA sequence comprises of four principle chemical molecules (adenosine [A], thymine [T], cystosine [C] and guanine [G]) called nucleic acids. There are in total three billion nucleic acids linked together in one sequence that is unique to human beings.
The DNA sequence instructs our cells to produce proteins that carry various functions in the skin such as:
Introduction: variations in Human DNA Sequence
An interesting point to note is that the human DNA sequence is 99.9% identical across all human beings. The 0.1% variation in the sequence of human DNA is one of the major reasons of the variability that is observed in the physical traits and biological functioning of humans across the world. Variations in the human DNA sequence are a result of a natural process which takes place throughout our lifetime and across generations.
Since DNA is passed on from one generation to another, the DNA variations we carry could have been acquired by our parents, or our grand parents or even our great great grand parents. One of the most common variations found in the general population are known as single nucleotide polymorphisms (SNPs, pronounced as snips)