The information on each chromosome is broken up into genes. Genes are specific segments of DNA.

It is the genes that do all the work. Your genes determine what hair color you will have, how tall you will be, what eye color you will have, everything about you. These differences are called traits. Traits are the physical representations of your genes.

For more information on how Genes work, check out The Gene School. This site gives an overview of genetics, cell replication, and protein synthesis. It also has a page of related links if you want to learn more.