A genome is the whole set of genetic instructions for an organism. Each organism's genome contains all the information necessary for its construction and growth and development.

Our bodies are composed of millions of cells (100,000,000,000,000), each with its own complete set of instructions for constructing us, similar to a recipe book. This collection of instructions is referred to as our genome and is composed of DNA. Every cell in the body, including skin cells and liver cells, includes the identical set of instructions:

DNA comprises the genetic instructions in our genome. Within DNA is a unique chemical code that guides our growth, development and health.

This code is established by the order of the four DNA nucleotide bases: adenine, cytosine, guanine, and thymine, or A, C, G, and T for short.

The structure of DNA is in the form of a double helix. Individual strands of DNA are wound into structures known as chromosomes.

Each cell's nucleus is where your chromosomes are situated. Sections of DNA within our chromosomes are "read" together to produce genes.

Different features, such as eye colour and height, are controlled by genes. Every living thing has its own unique genome. The human genome is composed of 3,2 billion DNA bases, whereas the genomes of other creatures vary in size.

If the 3,2 billion letters in your DNA were printed out, they would: Stack paperback books to a height of 200 feet (61 metres). Fill 200 500-page telephone directories If we recited at a rate of one letter per second for 24 hours every day, it would take a century. This is approximately the distance between London and the Canary Islands, Washington and Guatemala, or New Delhi and Hanoi.