An organism's DNA stores all information necessary to built and sustain life, 

may it be a simple bacterium, a tree or a bird. 

The recipe for live is written in a linear sequence of 4 different letters arranged on two intertwined strings. 

This helical molecule is constantly modified to open and close certain chapters either temporary or constantly. This plasticity allows that all structures in an organism contain identical DNA sequences but can behave very differently, 

like leaves and roots of a tree. 

In contrast to deliberate modification DNA can also be damaged by environmental impacts such as UV light emitted by the sun or toxic chemicals. Unrepaired damages change the meaning of the words, result in faulty recipes and ultimately can cause abnormal structures, like cancer, to form.

I hope you enjoy taking in this illustration as much as I did creating it...

And maybe I could even spark your curiosity about molecular biology and the fundamentals of life.