The energy in coal<span> comes from energy that was stored in giant plants that lived hundreds of millions of years ago in swamp forests, even before the dinosaurs! When these giant plants and ferns died, they </span>formed<span>layers at the bottom of the swamps. Water and dirt began to pile up on top of the dead plant remains.</span>
The traits of a living thing depend on the complex mixture of interacting components inside it. Proteins do much of the chemical work inside cells, so they largely determine what those traits are. But those proteins owe their existence to the DNA (deoxyribonucleic acid), so that is where we must look for the answer.
The easiest way to understand how DNA is organized is to start with its basic building blocks. DNA consists of four different sugars that interact with each other in specific ways. These four sugars are called nucleotide bases and have the names adenine (A), thymine (T), cytosine (C) and guanine (G). Think of these four bases as letters in an alphabet, the alphabet of life!
